Architect vs technical architect: who does what on a building project?

An architect primarily defines the design, spatial organisation and overall technical concept of a building. A technical architect or building surveyor focuses more closely on construction execution, quantities, quality, site coordination and cost control. Their responsibilities overlap, but they are not interchangeable: on many projects they work together as part of the same project management team.

What is the difference between an architect and a technical architect?

The clearest distinction is their main area of responsibility:

• The architect develops and coordinates the architectural design.
• The technical architect helps turn that design into a controlled, measurable and properly executed construction process.

An architect usually works from the intended use, layout, appearance, planning constraints and technical requirements of the building. A technical architect concentrates on how the work will be built, measured, checked and documented on site.

The exact professional titles, statutory duties and signature requirements vary by country. Before appointing either professional, confirm which qualifications and approvals are required for the type of work and location of the property.

What does an architect do?

An architect is responsible for shaping the building solution. Depending on the scope of the appointment, their work may include:

• Studying the client’s needs and the existing property.
• Developing layouts, circulation and use of space.
• Preparing concept, planning and construction drawings.
• Coordinating structural and building-services information.
• Selecting materials, systems and architectural details.
• Preparing documents for planning or building approvals.
• Checking that the design remains coherent during construction.
• Reviewing design changes proposed on site.

For a home renovation, the architect might decide whether a wall should be removed, how a new kitchen connects to the living space, where openings should be placed and how the proposed work affects the rest of the building.

The architect is therefore usually the main design reference. However, that does not mean the architect automatically manages every measurement, invoice, safety matter or quality check unless those services are included in the appointment.

What does a technical architect or building surveyor do?

The role commonly described in Spain as an aparejador or arquitecto técnico does not have an exact equivalent in every country. Depending on the market, comparable functions may be performed by a building surveyor, construction manager, quantity surveyor or architectural technologist.

Typical responsibilities include:

• Reviewing the buildability of the proposed design.
• Preparing or checking measurements and bills of quantities.
• Supporting tender comparisons and contractor selection.
• Monitoring construction progress.
• Inspecting workmanship, materials and completed elements.
• Recording defects, site instructions and pending decisions.
• Checking progress claims against work actually completed.
• Tracking variations and their effect on the budget.
• Coordinating technical information between the design team and contractor.
• Supporting handover, snagging and close-out documentation.

This professional provides an important link between drawings, site activity and financial control. Their work is especially valuable when a project includes several trades, staged payments or frequent changes.

Why does the distinction matter?

A renovation can have a good design and still suffer from poor execution. It can also be well built but fail to meet the owner’s functional needs because the design was not sufficiently developed.

Understanding the two roles helps the homeowner assign responsibility clearly:

Project area	Architect	Technical architect
Spatial design and layout	Leads	Reviews buildability
Architectural drawings	Leads	Uses and checks for execution
Design coordination	Leads	Supports site coordination
Measurements and quantities	May prepare or review	Often prepares or verifies
Cost monitoring	May oversee design impact	Often tracks actual costs and variations
Site quality control	Reviews design compliance	Closely monitors execution
Progress certification	May participate	Often verifies completed work
Defects and snagging	Reviews relevant design issues	Inspects and records execution defects
Contractor instructions	Issues design clarifications	Coordinates and documents site actions

The final allocation depends on the contracts and local professional framework. Responsibilities should never be assumed only from a job title.

When do you need an architect?

An architect is normally advisable when the project requires substantial design decisions or affects the building as a whole. Common examples include:

• Building a new home.
• Extending an existing property.
• Changing the internal layout significantly.
• Altering façades, roofs or major openings.
• Changing the use of a space.
• Intervening in structural elements.
• Coordinating complex accessibility, fire-safety or building-services requirements.
• Preparing a complete design for regulatory approval.

An architect can also be useful for a smaller renovation when space is limited, the brief is complex or the owner wants several design options assessed before construction begins.

For example, combining a kitchen, corridor and living room may appear simple. In practice, it can affect structure, ventilation, lighting, services, finishes and circulation. An architect can integrate those decisions into one coherent proposal.

When do you need a technical architect?

A technical architect is particularly useful when execution, measurement and financial control are the main risks. Consider appointing one when:

• The contractor’s quotation contains unclear or incomplete quantities.
• Several contractors or specialist trades must be coordinated.
• The renovation will be paid through staged progress claims.
• The design includes many technical details or interfaces.
• You need independent checks of workmanship and materials.
• Variations are likely during construction.
• The property has existing defects that must be documented.
• You need structured snagging and handover support.

Even on a project with an architect, the technical architect can provide more continuous attention to site production, measurements and cost movements.

Can an architect and a technical architect work together?

Yes. On many renovations and building projects, this is the most effective arrangement.

A typical workflow is:

1. The homeowner defines the objectives and budget.
2. The architect develops the design and project documentation.
3. The technical architect reviews buildability, measurements and execution risks.
4. Contractors price a consistent scope of work.
5. The professional team compares offers and identifies exclusions.
6. Construction begins with agreed drawings, quantities and responsibilities.
7. The architect resolves design questions.
8. The technical architect monitors progress, quality, quantities and variations.
9. Progress claims are checked before payment.
10. Both professionals support snagging and handover within their respective scopes.

This division reduces the gap between design intent and site reality.

How to decide which professionals your project needs

1. Define the scope before requesting quotations

List the rooms, elements and systems that will change. Distinguish between cosmetic work and interventions affecting layout, structure, envelope or services.

A vague request such as “complete renovation” is not enough to assign professional responsibilities or compare contractor prices.

2. Identify the main project risks

Ask what could cause the greatest problem:

• Poor spatial decisions.
• Missing approvals.
• Structural uncertainty.
• Incomplete quantities.
• Low-quality workmanship.
• Uncontrolled variations.
• Delayed decisions.
• Payments that exceed actual progress.

Design risks usually point towards stronger architectural involvement. Execution and cost risks often justify a technical architect. Complex projects commonly need both.

3. Request a written scope of services

The appointment should state who will:

• Produce each drawing and specification.
• Measure the work.
• Prepare tender documents.
• Answer contractor queries.
• Visit the site and how often.
• Approve samples and substitutions.
• Record instructions.
• Assess variations.
• Check progress claims.
• Prepare snagging lists.
• Close out the project.

This prevents two professionals from assuming that the other is handling a critical task.

4. Connect design decisions to the budget

Every material, dimension or technical change can affect quantities and cost. The project team should maintain a usable budget throughout construction rather than treating the original quotation as a fixed reference that is never updated.

A controlled budget should distinguish between:

• Original contracted work.
• Approved variations.
• Pending quotations.
• Work completed to date.
• Amounts previously certified.
• Current payment due.
• Forecast final cost.

Collaborative budgeting software such as Presuo helps teams keep quantities, changes, progress certificates and current costs connected during execution.

Practical example: renovation with design changes

A homeowner plans to renovate a flat with an initial contractor budget of €90,000. The architect redesigns the kitchen and opens it towards the living room. During demolition, the team discovers that services must be rerouted and part of the proposed opening needs a different technical solution.

The architect should assess how the discovery affects the design and coordinate the revised drawings. The technical architect should verify the resulting quantities, review the contractor’s price, record the change and assess its effect on progress and forecast cost.

The change should not be treated as a verbal agreement. It should be documented with:

1. A clear description of the revised work.
2. Updated drawings or instructions.
3. Added and omitted quantities.
4. Agreed unit prices or a justified quotation.
5. Approval status.
6. Impact on programme.
7. Inclusion in the next progress certificate and cost forecast.

This is where the two roles complement each other: one protects the design solution, while the other helps control its execution and financial consequences.

Common mistakes when appointing these professionals

Assuming they perform the same role

Their skills overlap, but their main responsibilities differ. Hiring one professional without checking the required scope can leave gaps in design, site control or budgeting.

Choosing only on professional fees

A lower fee may exclude site visits, quantity checks, tender support or variation control. Compare the services included, not only the headline price.

Starting construction with an incomplete design

If key materials, details or layouts remain undecided, the contractor will price assumptions. Those assumptions often become variations later.

Failing to define who controls the budget

A contractor quotation is not the same as independent cost control. Someone should maintain the current contract value, approved changes, pending risks and forecast final cost.

Approving changes verbally

Verbal changes are difficult to price, certify and audit. Every change should have a description, cost, status and supporting documentation.

Paying without checking actual progress

A payment request should be compared with completed quantities and agreed milestones. Materials ordered or delivered should be treated according to the contract, not automatically counted as fully completed work.

FAQ

Is a technical architect the same as an architect?

No. They have different training and professional functions, although both work with buildings and may share some tasks. The architect generally leads architectural design, while the technical architect focuses more closely on execution, measurement, quality and cost control.

Can a technical architect design a renovation?

A technical architect may develop certain technical documents or renovation solutions within the scope permitted by local rules and their professional competence. Projects involving major architectural, structural or regulatory decisions may require an architect or other specialists.

Do I need both for a small bathroom or kitchen renovation?

Not necessarily. A straightforward replacement of finishes and fittings may only require a competent contractor. Professional input becomes more valuable when the work affects layout, structure, waterproofing, shared building elements, complex services or regulatory approvals.

Who chooses the contractor?

The homeowner makes the appointment. The architect and technical architect can help prepare comparable tender information, analyse offers, identify exclusions and assess whether the proposed price and programme are realistic.

Who checks the contractor’s invoices?

This depends on the agreed services. A technical architect often checks quantities, progress and variations, but this task must be expressly included in the appointment.

Who is responsible if something goes wrong?

Responsibility depends on the cause of the problem, each party’s contractual duties and the applicable local framework. Clear scopes, written instructions and traceable approvals make responsibilities easier to determine.

Conclusion

An architect and a technical architect address different but connected parts of a construction project. The architect protects the design, spatial solution and overall technical coherence; the technical architect helps control buildability, quantities, site quality, progress and cost.

For a simple renovation, one professional may be sufficient. For a complex refurbishment, extension or new build, involving both can give the homeowner stronger control from the first design decision to the final progress certificate and handover.