Schematic map with a coat of arms, alongside a tablet, safety helmet and notebook.

Explosive ordnance surveying in Bremen

An extension in Bremen may involve ground interventions beyond the new building footprint, for utility connections, paths or individual construction phases. FONTANA-EOD checks with you which areas existing ordnance records cover and where further investigation is needed.

Existing assets

Distinguish investigated areas from outstanding areas.

Construction phases

Coordinate the timing of earthworks and access.

Changes

Compare revised drawings with existing findings before work starts.

Discuss an extension or alterationOrdnance assessment in the state of Bremen
Assess the construction project

Include groundworks beyond the extension too

An extension may require new foundations, demolition and additional utility connections. For your Bremen project, we compare all planned interventions with existing records. Assign results to individual construction phases and the necessary official steps.

Project references

Selected project examples

Project site

Connect the site with the specific construction task

Schematic map with a coat of arms, alongside a tablet, safety helmet and notebook.

Identify the Bremen property and its connections clearly

Preparation describes the exact property location and all areas of ground required. Official preliminary clarification and subsequent technical tasks remain tied to this project. Results from other Bremen sites are not transferred. The position, depth and execution of your groundworks determine the investigation required for the project.

For construction projects in the city of Bremen, provide the property location and proposed groundworks together. Identify the street, house number and plot, and the building, external and connection areas affected. Bremen Police’s explosive ordnance disposal service handles preliminary clarification for the municipalities of Bremen and Bremerhaven; the specific enquiry remains tied to the property identified. For projects in the surrounding part of Lower Saxony, check the actual project location and its responsibilities separately. The historical aerial photograph analysis relates available evidence and outstanding questions to the planned ground interventions. Identify project locations in Mitte, Östliche Vorstadt, Neustadt, Walle, Gröpelingen, Hemelingen, Huchting, Obervieland or Bremen-Nord with Vegesack, Blumenthal and Burglesum by their specific address. Enquiries from Delmenhorst, Stuhr, Weyhe, Lilienthal or Achim fall under the responsibilities of the respective municipality in Lower Saxony.

For regional information relevant to your construction project, the Bremen City overview leads to further local information.

Bremen and Bremerhaven
Local context

Plan the extension and utility connections together

Building and connections as a coordinated task

If a proposed extension needs a new supply connection, for example, the excavation alone may be an insufficient investigation area. Include the utility trench to the connection point in planning too, even where another design team is responsible for it.

The Bremen State Archive discusses the destruction of western Bremen during the bombing on the night of 18–19 August 1944. For extensions and alterations today, relate local historical evidence to the property affected. Where records identify later development, utility installation, demolition or changed ground layers, compare these with today’s intervention. Earlier investigation results remain tied to their documented area and depth. For projects near water, compare existing records of quays, waterfront structures and sheet pile walls with the proposed foundations or intervention depth. Assign port, cargo handling, shipyard, industrial and logistics uses and freight and siding tracks identifiable in the records to the area affected. Information on fill, backfilling, dike construction, demolition or later restructuring helps account for buried or changed ground layers in the investigation.

Preliminary clarification and complete earlier records

Bremen Police explains its preliminary review using aerial photographs, archives and other findings. For a construction project, relate this information to the works actually proposed. Provide existing reports and information with all appendices. A note stating “already checked” does not identify the areas and depths actually covered.

Working together

Distinguish the tasks of client, designers and specialist contractor

Client and operator

The client describes the project and provides the available project records. The operator adds requirements for use, access and timing. A coordinating contact brings the parties together; individual tasks remain assigned to the named parties. Before commissioning, it is clearly recorded what information is missing, who will obtain it and what decision the result is intended to prepare.

Planning and construction management

The specialist designers describe areas, depths, construction methods and changes. Site management coordinates the planned sequence with the construction contractors and agreed specialist works. Results are assigned to the respective intervention. A technical plan change is communicated early enough for its effect on the survey task to be assessed before construction. Organisational construction stage boundaries remain distinguishable from technical survey boundaries.

Specialist company and competent bodies

The private explosive ordnance specialist contractor performs the agreed investigation and documentation work. Official requirements and decisions are clarified with the respective responsible bodies. The records needed for a specific procedure depend on the location and project. The technical report documents the specialist work carried out and its area, depth and limits of conclusions. The responsible bodies make official decisions concerning subsequent groundworks.

In Bremen, statutory responsibility generally lies with Bremen Police. Its explosive ordnance disposal service assesses the grounds for suspicion and determines official requirements. For measures on areas with suspected ordnance covered by section 5 of Bremen’s Explosive Ordnance Act, coordinate surveying by a suitable contractor, communication of results and official clearance.

Investigation task

Which specialist task comes next?

Read preliminary clarification and earlier reports in full

Assemble official preliminary clarification and technical reports with their appendices. Compare the property, intervention area and depth together. A brief reference to an earlier assessment is insufficient to determine its scope. Identify missing appendices before agreeing further services.

Relate existing information to the property and today’s intervention design. An overview can identify the sections with records and the appendices still needed. Compare the assessed area, earlier investigation commissions and current construction task. Identify missing evidence before commissioning further specialist works. Involve the responsible authority with the actual proposed works and available records for them.

Assess historical documents

Adapt the investigation to the construction phase

The task depends on the interventions actually needed and site conditions. Installations and access may differ between the building edge and an external connection. Agree a suitable approach for these areas. Explicitly retain the required official assessment alongside the private scope of services.

For an investigation beside an existing building, identify visible obstacles and known utility lines with their positions. The specialist contractor checks measurement conditions and which method can address the investigation objective. Agree necessary preparatory works and access with site management. The commission identifies the areas and depths to be covered and the results handover needed. If execution changes, compare this scope with the change again before the affected groundworks.

Compare investigation methods
Project types

Consider the extension through to its last connection

Illustration: a person wearing a hard hat and holding a tablet beside a cordoned-off excavation with an excavator.

New foundations beside existing buildings

Draw the new excavation and working spaces beside existing buildings. Compare earlier reports with this area using their appendices. Existing structures may help identify the location but do not establish that adjoining ground has been investigated. Keep different depths identifiable. Include preparatory demolition as a separate intervention where underground components are to be removed.

For preparation, also identify shoring, working spaces and the proposed removal of underground components. Draw their respective boundaries on the same site plan and identify different depths. Compare existing results using the full report’s appendices. The outstanding task for the extension can then be located. If further design requires additional areas, provide the change to the specialist contractor before the affected intervention.

Provide specialist supervision of excavation
Illustration: two people with a tablet beside a drawing table and a survey trolley on a construction site.

Utility connections beyond the excavation

A utility trench may extend beyond the building footprint to a distant connection point. Include chambers and additional pits on the same overview. Appropriate findings are needed for these areas even if another design team handles the utility. A shared project name does not replace geographical identification. Keep transitions between commissioned sections traceable on the drawing.

For a new connection, provide its start and end points, route and required depth. Give chambers, pits and widening their own positional references. Identify the design team updating these records and who receives changes. Provide investigation results for the utility section actually planned. If its position changes, compare newly affected areas with earlier findings and agree the necessary additional specialist works.

Specialist services and investigation tasks
Illustration: two people review plans and documents at a table beside a construction vehicle.

Construction while use continues

Existing building use may restrict access and working spaces. Describe which areas are accessible when and which routes remain in use. Adapt the investigation accordingly. Operational permission for access and technical prerequisites for groundworks remain separate tasks. Clarify both before each stage of work.

State which access routes are needed during the investigation and which operational routes should remain open. Identify the positions of temporarily closed areas or those covered by structures. Technical planning clarifies a suitable investigation under these conditions and records remaining limitations. Agree the investigation needed for preparatory groundworks before they start. Assign required results and operational permissions for access to each stage of work.

Coordinate the sequence and tasks
Preparation

Prepare the scope and commission together

Establish what needs to be known before commissioning the work

First establish which decision the commission needs to support. Is the task an initial assessment of existing documents, an investigation of a specific area or examination of an anomaly that has already been assessed? These tasks require different evidence. A general wish for safety does not define an investigation that can be carried out. The enquiry therefore specifies the groundworks, location, depth and available findings. Suitable specialist work and the required reporting are then agreed on that basis.

Define the specialist task

Coordinate preparatory work with the investigation

Required access and survey conditions are clarified before the site visit. This may include keeping areas clear, obtaining service information and coordinating with other trades. The method and site determine which preparations are actually needed. Changes to the surface or additional groundworks are not undertaken unilaterally simply to prepare for a survey. Their sequence is agreed with the specialist designers and responsible parties.

Clarify preparatory work in the programme

Agree a clear scope and schedule

A reliable process distinguishes work already technically clarified from prerequisites still unresolved. If an area will only be partly accessible, this must be taken into account when commissioning the work. Handover and assessment of results also need time in the construction programme. Specific coordination connects the described scope with access, records, execution conditions and the date by which a decision is needed.

Discuss the scope and schedule
Tasks at the site

These drawings and details are needed

01

Extension and demolition boundary

Show the new construction area and areas where existing foundations or other underground components are to be removed. Distinguish visible existing buildings from the ground interventions actually proposed. This identifies the areas needing investigation for the extension.

02

Utility lines through to the connection point

Show the proposed utility route with chambers and excavations. A connection point outside the new building footprint may require additional investigation. Existing utility drawings help preparation but do not, alone, establish that ordnance assessment has taken place.

03

Construction phases and access

Identify which sections are accessible when and which areas are to remain in use. Coordinate the investigation with these time windows. Site management must always be able to identify which section has already been investigated and which remains outstanding.

04

Existing reports and drawing revisions

Assign the corresponding drawings and depth information to older results. Identify any differences in the current design. State in the enquiry if appendices or parts of a report are missing. Without them, the earlier investigation scope cannot be established reliably.

Project documents

Documents that establish the next step

Provide design teams with the same revisions

Building and utility designs should refer to traceable drawing revisions. If connections are added later, provide the change to the technical planners involved before work starts. A common overview shows responsibility for each intervention. Keep the corresponding reports available in full rather than replacing them with a general progress note.

Identify the responsible designers for buildings, external works and connections. Give each drawing passed on a date and an unambiguous revision. The project overview shows which change affects which construction phase and which records it needs. Site management receives the technically coordinated results for each forthcoming ground intervention. Keep earlier reports and their appendices traceably available with their corresponding investigation commission.

Distinguish completed sections from outstanding sections

Identify the documented investigation scope of each construction phase. Do not transfer a result for the extension to the later utility trench. Site management needs the appropriate maps, depth information and limitations for each. Outstanding transitions remain visible even if other parts of the project are further advanced.

For handover, show areas covered, depths reached and limitations together. Identify partly accessible areas separately. Also state which investigations remain to be carried out and which response they require. Compare the next construction phase with these results. Keep the commissioned measurement data, survey results and interpretation of findings linked to the full report and its drawings. After clearance works, the clearance record, including scope, results and limitations, supplements the evidence for the construction phase actually covered. Before execution, relate a relocated utility or additional pit individually to the existing investigation records.

Construction sequence

Coordinate investigation and construction sections

Before demolition and site establishment

The first ground intervention may precede the extension itself. Identify underground components, temporary connections and working areas. Schedule the results needed for them in time. An investigation date for a later phase cannot replace the prerequisites for earlier interventions.

Coordinate the construction phase with us

When moving from building construction to connections

Provide the next parties with the current utility route and appropriate reports. Compare a relocated connection point or additional chamber with existing findings before execution. The technical conclusions remain limited to the documented area and depth. Include any official coordination still required.

Coordinate the construction phase with us
Method selection

Select methods according to the task and survey conditions

Historical records and aerial photographs

Historical aerial photograph assessment and other old records help place the basis for suspicion in its spatial context. The available images, their evidential value and the limits of the area considered matter. The absence of an identifiable indication must be distinguished from a technically surveyed ground area. The assessment is considered together with the planned intervention and other available findings. It can support the choice of a survey, but is not a measurement of the present-day subsurface or confirmation for all future works.

Understand aerial photograph assessment

Magnetometric survey

Magnetometric methods detect magnetic anomalies. Whether they can address the specific survey task depends, among other things, on the expected objects, ground conditions, interference and required survey area. Fences, utilities or existing structures may affect interpretation. A measurement signal is therefore not described as ordnance solely because of its strength. Method, interpretation and any further investigation are planned as a connected specialist task.

Understand the scope of magnetometry

Electromagnetic methods

Electromagnetic investigations can be suitable for particular metallic targets and site conditions. Their suitability must be explained for the task, rather than inferred simply from the availability of equipment. Interfering installations, accessible areas and the findings required must also be considered. Results are documented with their location and survey conditions. The specialist assessment determines whether a supplementary method is needed; this remains a project-specific decision.

Understand electromagnetic surveying

Ground-penetrating radar

Under suitable conditions, ground-penetrating radar can provide information about subsurface structures and reflections. Ground conditions, moisture, installations and the particular survey task affect interpretability. An anomaly is not automatically ordnance, and an area with no apparent anomalies is not general evidence for arbitrary depths. The specialist interpretation and its limits are documented with the instruction. A survey for another purpose is not adopted without checking as ordnance evidence.

GPR and limitations

Deep-ground and downhole surveys

For deeper groundworks, it may be necessary to establish whether a surface investigation can provide the required findings or another approach is needed. Preparation includes the location, depth, borehole layout and existing services. Creating access for the investigation must also be properly planned by specialists. A general depth figure or standard grid cannot replace that work. Findings remain limited to the areas actually investigated and the method used.

Prepare deep interventions

Survey during construction

If a necessary preliminary investigation cannot be completed in full, assess whether a technically planned approach alongside construction is suitable. This includes the agreed investigation, interpretation and communication of findings within the proposed working sequence. Necessary surveying remains part of the agreed approach; visual inspection supplements it. Site management needs a clear description of when specialist works occur, how new findings are handled and which areas remain outstanding. For ordnance clearance during construction, the DGUV FAQs explain the necessary technical investigation works. Visual observation alone does not meet the state of the art for this specialist task.

Agree the approach during construction
Technical assessment

Check changed drawings before earthworks

Review aerial photograph analysis and technical reports

The historical aerial photograph analysis and technical investigation reports rely on different evidence. Check which areas, conditions and questions each document covers and whether it suits the works now proposed.

Where historical evidence is incomplete, carry out the research and aerial photograph analysis required. Relate existing files, images and results to the specific property and proposed construction phases. Include identifiable later ground changes in this comparison. Record the findings still needed before the forthcoming works and the resulting technical steps. Official preliminary clarification and commissioned technical investigations retain their respective purposes and geographical coverage.

Check measurement conditions in every construction phase

A surface survey may face different conditions in open areas from those between utility lines, metal installations or obstacles. Identify apparent restrictions in the sections concerned. Whether a method is suitable and which additional steps are needed is a technical decision.

For method selection, describe expected target objects, soil structure, interfering objects and the required investigation depth. Existing utility lines, reinforcement and metal installations can affect measurements and interpretation. For deeper interventions, check whether suitable findings can be obtained from the surface or whether a borehole survey, for example, is needed. Agree the proposed investigation positions, access and preparatory works with the design team. Account for their own ground interventions before creating them too.

Account for new utility routes and depths

If a connection is relocated or an excavation extended, compare the change with areas previously investigated. The additional need for surveying must be clarified before these works. A changed construction drawing does not expand the investigated area of an older report.

Compare the new position and depth with complete results plans. Assign suitable existing findings to the revised works. For additional areas, the technical planners identify the outstanding investigation needs. Assess the specialist works performed and document their methods, measurement conditions and limitations. For measures on areas with suspected ordnance, account for official decisions required under Bremen’s Explosive Ordnance Act before the affected construction starts. Site management receives the applicable results for the subsequent works.

Next steps

Coordinate construction phases and investigations

01

Coordinate initial contact and existing records

Assemble preliminary clarification, technical reports and accompanying appendices. For the first discussion, identify the property location, plots and decision needed before the next intervention. Project management brings together contacts for the building, connections and construction sequence. Provide available results of official preliminary clarification with their appendices.

02

Check interventions and historical evidence

Mark the extension, demolition and connections in the current design. Compare complete ordnance records with the planned areas and depths. Where historical evidence is incomplete, carry out the necessary research and aerial photograph analysis. Relate findings and outstanding questions to today’s construction task.

03

Define a suitable method and construction phases

Define when each area is accessible and can be investigated. Select the method against the investigation objective, target objects, soil structure, interference and required depth. Coordinate preparatory works and investigation areas with the design team and official requirements.

04

Carry out investigations and assess results

Carry out the commissioned surveys or technically planned accompanying works within the agreed scope. The specialist contractor assesses measurement data and findings with regard to the methods and investigation conditions. Document limitations with their positions. Report actual explosive ordnance or suspicious objects to the responsible authority immediately.

05

Hand over reports and drawings in full

The documentation identifies areas and depths covered, methods, results and limitations. Hand over the ordnance survey report and, where applicable, clearance record with their accompanying drawings. Account for communication of results to the authority required under section 5 of Bremen’s Explosive Ordnance Act for the task concerned.

06

Clarify the next decision and changes

Clarify differences on technical grounds before the affected construction works. Before the next phase, compare the documented results, outstanding technical tasks and necessary official decisions. For construction measures on areas with suspected ordnance, obtain the statutory clearance from the responsible authority. Account for new areas and depths before work on them starts.

Documentation

Document results for every construction phase

Findings and their scope

For site management, record investigated sections, depth references used and remaining limitations traceably. Where several sections are handled separately, their records must be assignable unambiguously. A combined overview may help but does not replace the corresponding results reports and their limitations.

Project responsibilities

For areas with suspected ordnance, section 5 of Bremen’s Explosive Ordnance Act regulates commissioning a suitable contractor, communicating the results and official clearance before the construction measures it covers. A technical report and an official decision serve different purposes. Account for the necessary coordination when scheduling.

Working approach

How FONTANA-EOD works

Document the agreed specialist service clearly

We assess the planned groundworks against the available documents and their design revision. Before attending site, we agree with you what needs to be investigated, which areas are accessible and what findings are required. If the design or site conditions change, we check whether the agreed scope remains appropriate. The report states what was actually investigated and the limits of the findings. This allows designers and site management to see which findings they can use and where questions remain.

Discuss the investigation task

The task before the equipment

We first establish the investigation objective: which question must it answer? We then select a technically suitable method. The availability of a particular device or experience on a similar neighbouring site is not enough to justify the choice of method on its own.

Keep limitations visible

Inaccessible areas and limited findings are identified. They are shown separately in the report and overview plan. Planners and site management can then decide specifically which areas still need work and when a suitable investigation will become possible.

Clarify changes before intervening in the ground

A new location, additional depth or different construction methods are compared with the existing results. Changes are passed on with dates and clear plan references. Feedback is provided before the affected work so that an unresolved question can be incorporated into the workflow.

Hand over the report and plan together

The technical conclusion remains connected to its location references and appendices. A brief summary helps orientation but does not replace the documented survey scope. This basis is retained even if site management or contractors change.

Understand the results

Use technical statements for the next decision

A connection is a distinct ground intervention

A building’s shared utility supply does not mean the entire utility route lies within the investigated excavation. Show its route, depth and associated structures. Comparison identifies which existing findings apply and which area still needs consideration.

Understand investigation reports and their limitations

An overview supplements the full reports

A common drawing helps site management identify the works. It refers to the individual investigations and identifies outstanding sections. It replaces neither their appendices nor technical limitations. Following a later change, compare the documented scope with the proposed works again.

Understand the service scope
Design and findings

Documents for the next construction decision

Illustration: aerial photographs and maps on two screens and printed on a desk.

Historical evidence and the current design

Aerial photograph interpretation is related to the actual groundworks. Its purpose and geographical scope remain distinct from a technical investigation of the ground as it is today.

Understand aerial photograph assessment
Illustration: two people review plans and documents at a table beside a construction vehicle.

Specialist reports for site management

The findings, their locations and limitations are handed over together. This makes clear to those carrying out the work which area has been investigated and which task remains outstanding.

Assess investigation reports
Four people in orange high-visibility vests in front of two excavators on a construction site.
Person with a yellow survey cart on a footpath in front of a hedge.
Questions from planning

Questions about extensions and construction phases in Bremen

Is an older report sufficient for a new extension?

First compare it with the current construction area and planned depths. Include connections and demolition works too. Whether it covers the new task depends on its documented scope and technical assessment.

Can the investigation take place in several construction phases?

Agree this for the project. Access, the necessary investigation and official requirements are decisive. Results must be assigned clearly to each section. Completing one section establishes nothing about areas not yet investigated. Coordinate the proposed works with Bremen Police’s explosive ordnance disposal service beforehand. For construction measures on areas with suspected ordnance covered by section 5 of Bremen’s Explosive Ordnance Act, official clearance before starting is decisive.

Why must utility connections be identifiable separately on the drawing?

Because their routes may extend beyond the building area itself. Position, depth and additional chambers or excavations determine the ground affected. Only this makes it possible to establish whether existing findings also cover this part of the project.

What should happen if a utility route changes at short notice?

Mark the new route on the drawing and have it compared with earlier investigation results before earthworks. Clarify whether further investigations or official coordination are needed. This applies to short-notice changes too.

Who should I contact about a possible explosive ordnance find?

Stop work in the affected area, keep your distance and notify the police on 110. Do not touch or relocate the object. Follow the instructions of the responsible authorities.

Must a new chamber outside the extension be considered separately?

Compare its position, excavation and depth with the existing investigation areas. If it lies beyond the documented scope, clarify additional requirements before groundworks. Being part of the extension does not expand the old report. Soil structure, metal installations and interference can limit measurements. The specialist contractor relates the method and remaining limitations to the specific investigation task.

Which details help when design teams are separate?

Common drawing revisions, unambiguous section identifiers and contacts for the building, connections and construction sequence are helpful. Pass changes to the affected parties before work starts. The process reviews records, plans and carries out necessary specialist works, and assesses results. Complete reports and drawings document the scope covered for the subsequent decision.

What determines the work involved in several construction phases?

The respective areas and depths, existing findings, access conditions and construction sequence. Assign official steps and private investigations appropriately. A complete overview helps define the commission. Suitable methods, interference, preparatory works required and documentation also affect effort and costs.

Project enquiry

Send records for your Bremen construction project

Send building and connection designs

Provide the site plan, demolition boundaries, new foundations and utility routes with their depths. Include complete official and technical records and additional working spaces. If an area with suspected ordnance has been designated, include its boundary and accompanying records. Identify the technical findings needed for the next intervention.

Identify the construction sequence and contacts

Identify the groundworks planned first and responsible design teams. Mark relocated connections and temporarily inaccessible areas. Outstanding tasks can then be assigned to the sections.

For each construction phase, record the revisions of available documents, official conditions and maximum intervention depths with their elevation datum. Submit dated as-built and utility drawings. The project overview identifies handovers needed, while individual records document technical findings and their limitations. This keeps central coordination and section-specific tasks traceable for subsequent trades.

Project enquiry

Have your project assessed

Whether historical aerial photograph analysis, explosive ordnance surveying, surface surveying using GPR, magnetometry or TDEM, deep-ground surveys, downhole surveys, excavation supervision, area clearance or ordnance recovery is needed depends on the location, ground disturbance, depth, ground and existing documents. An early ordnance assessment provides clarity for tendering, programming, occupational safety and construction.

FONTANA-EOD combines its Section 7 SprengG licence, specialists holding Section 20 SprengG certificates of competence, suitable survey and clearance methods, and traceable documentation. Send the site plan, depth of ground disturbance, construction phase and existing documents for an initial technical assessment.

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