INTERIOR DESIGN FROM LONDON Technical Drawings for Construction
Detailed Construction Drawings
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Technical drawings give builders the detail they need to construct your project
A design can look complete on a floor plan while still leaving many important construction questions unanswered.
How should the new wall be built?
How does the roof connect to the existing house?
What insulation is required?
How should a structural opening be formed?
How are drainage, ventilation and fire safety requirements addressed?
Technical drawings develop these details so that the project can move from an approved design to something that can be properly priced, coordinated and constructed.
Tholos prepares technical drawings for extensions, loft conversions, renovations and other residential building projects.
If you already have planning drawings or building drawings, we can review the information available and identify what additional technical design is required before the project goes to tender or construction begins.
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What are technical drawings?
Technical drawings provide detailed information showing how different parts of a building project should be constructed and coordinated.
They develop the architectural design beyond the general layout and appearance of the project.
Depending on the work, technical drawings may explain:
- wall construction
- roof construction
- floor build ups
- foundations
- structural openings
- insulation
- waterproofing
- waterproofing
- ventilation
- fire safety
- windows and doors
- junctions between materials
- connections between new and existing construction
The level of technical detail required depends on the project.
A straightforward internal alteration may need relatively limited information.
A substantial extension or whole house renovation may require a much larger coordinated package involving architects, structural engineers and other specialist designers.
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What is the difference between technical drawings and building drawings?
The terms are often used interchangeably, but there is a useful distinction.
Building drawings describe the wider set of drawings used to communicate a project for construction.
Technical drawings focus more closely on the detailed design of how specific elements should be built and how different parts of the project connect.
For example, a building drawing may show the position and dimensions of a new extension wall.
A technical drawing may then show:
- the wall build up
- insulation
- cavity construction
- internal and external finishes
- damp proofing
- how the wall meets the roof
- how it connects to the existing building
Both types of information can form part of the complete construction package.
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What is the difference between planning drawings and technical drawings?
Planning drawings are prepared primarily to explain what development is proposed.
They usually show:
- existing and proposed layouts
- elevations
- scale
- height
- appearance
- relationship with the existing property
- relationship with neighbouring properties
Technical drawings answer a different question.
They explain how the project should actually be constructed.
Planning drawings rarely provide the technical answers required during construction.
A project can therefore have full planning permission while still needing substantial design work before it is ready for a builder.
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Why are technical drawings important before choosing a builder?
A builder can only price what has been defined.
If important construction details are unresolved when contractors are invited to tender, each builder may make different assumptions.
One contractor may assume one type of roof construction while another prices something completely different.
One may include additional structural work.
Another may allow less insulation, different glazing or a lower specification finish.
The final quotations can then appear very different even though the builders are not actually pricing the same project.
Developing the technical design before tender helps reduce these uncertainties.
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What do technical drawings include?
The exact content depends on the project, but technical drawings may include details for:
- foundations
- external and internal walls
- floors
- roofs
- ceilings
- structural openings
- stairs
- windows and external doors
- insulation
- damp proofing
- drainage
- ventilation
- fire protection
- junctions between new and existing construction
- specialist construction elements
They may also refer to specifications, structural design and information produced by other consultants.
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Construction details
Construction details focus on specific areas of the project where more information is needed than can be shown on general plans and sections.
Typical details might show:
- how a wall meets a roof
- how an extension connects to an existing house
- floor and wall junctions
- window installation
- door thresholds
- insulation continuity
- waterproofing
- roof edges
- roof edges
- structural openings
These details can help resolve potential problems before they are encountered on site.
They also give builders clearer information when preparing quotations.
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Technical drawings for house extensions
House extensions often require detailed coordination between the new construction and the existing property.
Technical drawings may cover:
- foundations
- external wall construction
- floor construction
- roof design
- insulation
- structural openings
- connections to the existing building
- drainage
- glazing
- ventilation
- fire safety
- material junctions
Large openings between the existing house and new extension may also require structural design from an engineer.
Tholos can coordinate the architectural and structural information before the project is issued for tender.
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Technical drawings for loft conversions
Loft conversions often involve a particularly high level of technical coordination because the work affects the existing roof, floors, stairs and fire strategy.
Technical information may include:
- new floor construction
- structural strengthening
- roof alterations
- dormer construction
- rooflights
- stairs
- insulation
- ventilation
- fire protection
- doors
- ceilings
- junctions with the existing roof
The architectural design and structural design need to work together before construction.
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Technical drawings for renovations
Technical drawings for renovations
- structural openings
- altered floors
- new partitions
- ceiling construction
- insulation upgrades
- new windows and doors
- kitchen and bathroom alterations
- drainage
- repairs
- junctions between existing and new materials
Existing conditions are not always fully visible before work starts, so renovation projects may also require additional information as construction progresses.
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Structural design and technical drawings
Architectural technical drawings and structural design should be coordinated where structural work is involved.
The structural engineer may design elements including:
- beams
- columns
- foundations
- lintels
- floor strengthening
- roof structure
- structural openings
- retaining structures
The architectural drawings then need to reflect those structural requirements.
If this coordination happens after a builder has priced the project, changes can affect both the construction method and the cost.
Resolving as much of the structural design as possible before tender gives contractors clearer information to price.
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Technical drawings and Building Regulations
Technical drawings often contain much of the information required to demonstrate how a project will comply with Building Regulations.
Depending on the work, this may include requirements relating to:
- structural safety
- fire safety
- thermal performance
- ventilation
- drainage
- glazing
- access
- energy efficiency
Building Control checks relevant information and work, but it does not design the project.
Responsibility for producing and coordinating a compliant design sits with the relevant project dutyholders.
Who is responsible for coordinating the technical design?
Residential projects can involve several designers.
These might include:
- the architect
- structural engineer
- drainage designer
- energy consultant
- specialist suppliers
- other technical consultants
Their designs cannot be treated as completely separate pieces of information.
Structural design may affect architectural layouts.
Ventilation requirements may affect windows or mechanical systems.
Insulation can influence wall and roof dimensions.
Drainage can affect foundations and floor layouts.
Where more than one designer is involved, a competent Principal Designer may need to be appointed to plan, manage and monitor the design work for Building Regulations compliance.
Tholos can provide Principal Designer services where required and coordinate the technical information produced by the wider design team.
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When should technical drawings be prepared?
Technical drawings are usually developed after the main design has been established.
Depending on the project, this may be after planning permission has been obtained or after it has been confirmed that planning permission is not required.
The technical design should ideally be sufficiently developed before contractors submit final tenders.
This allows builders to price a clearer scope of works and reduces the number of unresolved construction decisions left until work begins.
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Can builders quote without technical drawings?
Yes, but the level of certainty will usually be lower.
A builder can provide an early estimate from planning drawings or outline information.
That can be useful when establishing whether the general project budget is realistic.
However, if important technical details have not been resolved, the builder may need to make assumptions or include provisional allowances.
As the technical design develops, those figures may change.
For contractor selection, a tender based on more complete information is generally easier to assess than an early estimate.
HOW WE SOLVE IT
Technical drawings and the tender package
Technical drawings can form an important part of the tender information issued to prospective builders.
A tender package may include:
- building drawings
- technical drawings
- structural design
- specifications
- schedules
- scope of works
- relevant approvals
- tender instructions
Selected contractors then receive the same information and can price the same defined project.
This makes it much easier to understand genuine differences between tenders.
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How Tholos develops technical drawings
The starting point depends on what information already exists.
We review the existing project
You may already have planning drawings, building drawings, structural information or planning permission.
We review what is available and establish what additional technical information is required.
We develop the architectural technical design
The drawings are developed to address the relevant construction requirements and details.
We coordinate structural design
Where an engineer is involved, the structural solution is coordinated with the architectural information.
We coordinate other designers
Where required, information from other consultants and specialist designers is incorporated into the wider project.
We prepare the project for tender
Once the design has been sufficiently defined, the information can form part of the package issued to prospective builders.
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Do technical drawings reduce construction problems?
They cannot remove every uncertainty from a building project.
Existing buildings can contain hidden conditions, and some decisions will inevitably need to be made during construction.
However, resolving technical questions before work begins can significantly reduce avoidable uncertainty.
It is generally easier and less expensive to resolve a construction detail on a drawing than after the builder has already started work.
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Why can incomplete technical design increase costs?
When information is missing, builders have to make assumptions.
Those assumptions may appear as:
- provisional sums
- exclusions
- allowances
- qualifications in the quotation
Alternatively, an item may not have been included at all.
Once construction begins and the missing requirement becomes clear, the contractor may need to price it as additional work.
A more developed technical design helps define more of the project before the building contract is agreed.
HOW WE SOLVE IT
Can Tholos help find builders after the technical drawings are ready?
Yes.
Once the project is sufficiently defined, Tholos can help identify and vet contractors whose experience, references and accreditations fit the scope of works.
Our network of contractors currently includes areas around:
- Nottingham
- Derby
- Durham
- London
Availability depends on the project, location, budget and construction programme.
HOW WE SOLVE IT
How does Tholos vet potential builders?
Contractor suitability should be assessed against the actual project rather than simply whether the builder operates locally.
Depending on the appointment, we can review matters such as:
- relevant experience
- comparable previous projects
- references
- accreditations
- insurance
- availability
- proposed programme
- quality of tender submission
The aim is to identify builders whose experience fits the scope of works.
HOW WE SOLVE IT
What happens after the technical drawings are finished?
Once the technical design and other required project information are sufficiently developed, the project can move to tender.
Tholos can help:
- prepare the tender package
- identify and vet contractors
- issue tender documents
- respond to queries
- review returned tenders
- compare scope and pricing
- support contractor selection
Once the preferred builder, price and scope have been agreed, we can also help prepare the building contract.
HOW WE SOLVE IT
What if I already have a builder?
You can still use Tholos for the technical design.
If your builder is asking for more detailed drawings or construction information, we can review what already exists and establish what is missing.
We can also help with:
- building drawings
- structural coordination
- Building Regulations information
- Principal Designer services where required
- scope of works
- quotation review
- preparation of the building contract
- support during construction
HOW WE SOLVE IT
Technical drawings in Nottingham
Tholos can prepare technical drawings for extensions, loft conversions, renovations and other residential projects in Nottingham and surrounding areas.
Where appropriate, we can also help prepare the project for tender and identify suitable contractors within our network.
Technical drawings in Derby
For residential projects in Derby and surrounding areas, Tholos can develop detailed technical information and coordinate structural design before contractors are invited to tender.
Technical drawings in Durham
Tholos can support residential projects in Durham with technical drawings, design coordination and preparation for construction.
Technical drawings in London
Residential alterations in London can involve complex existing buildings, significant structural work, conservation considerations and difficult junctions between new and existing construction.
Detailed technical design can be particularly valuable in defining these projects before tender.
Tholos supports residential projects in selected areas of London and can help identify suitable builders where available.
HOW WE SOLVE IT
Get your project ready for tender and construction
If you already have planning permission or building drawings but are unsure whether the project contains enough detail for construction, Tholos can review the information available.
We can identify missing technical design, coordinate structural and other specialist information and bring the project to the point where suitable contractors can prepare meaningful tenders.
Once the project is ready, we can help identify and vet builders, review tender returns and prepare the building contract.
Client experience
"
Lorem ipsum dolor sit amet, consectetur adipiscing elit. We had a vision for our home but no idea how to realise it. Tholos Interiors took complete ownership of the project — every detail was considered, every decision explained. The result exceeded everything we had imagined.
– Lawrence Ipsum, Homeowner · London –
Frequently Asked Questions
What are technical drawings?
Technical drawings are detailed construction drawings showing how elements of a building project should be constructed and coordinated. They may cover walls, roofs, floors, insulation, drainage, structural interfaces and other technical details.
Are technical drawings the same as planning drawings?
No. Planning drawings primarily explain the proposed development for planning purposes. Technical drawings contain detailed information required for construction and coordination.
Are technical drawings the same as building drawings?
The terms overlap. Building drawings is a broader description of drawings used for construction, while technical drawings tend to focus more specifically on detailed construction information and junctions.
Do I need technical drawings if I have planning permission?
Often, yes. Planning permission establishes whether the proposed development is acceptable in planning terms but does not normally provide all of the construction information a builder requires.
Can builders quote from technical drawings?
Yes. Technical drawings can form part of the tender package used by builders to prepare detailed quotations.
Do technical drawings include structural design?
Structural design is normally prepared by the structural engineer. Tholos can coordinate that information with the architectural technical drawings.
Who coordinates the technical design?
The project may involve several designers. Where required under Building Regulations, a competent Principal Designer must plan, manage and monitor the design work for compliance.
Can Tholos prepare technical drawings from existing planning drawings?
Yes. We can work with a contractor you have already selected and prepare the additional design information required for construction.
Can Tholos manage the tender process?
Yes. We can prepare tender information, identify and vet suitable contractors, issue the project for tender and compare returned quotations.
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