• Time charge (hourly rate)

  This option can work well in the early stages of a project. Time charge can provide flexibility where the viability of a project is unclear or a more iterative approach is needed to better define the brief and design. Whilst this provides less cost certainty to a client, your architect will keep you informed of the hours invested and agree milestone caps to control cost.

• Percentage of construction cost

  Percentage fees are linked to the anticipated construction costs (excluding VAT and professional fees) of a project which is generally proportional to the level of input required. These give better cost certainty to a client whilst retaining flexibility to adjust fees should the project scope and construction cost expand. Indicative percentages are outlined below.

• Lump sum (fixed fee)

  Where fixed fees are agreed at the beginning of a project, this provides the client and architect certainty of costs in return for a defined set of information. Should additional information be required from that previously agreed, the architects fee would be adjusted accordingly. A lump sum works well on non complex projects with a well defined brief or outcome.

Extension projects:

Where projects involve working with existing buildings in confined sites with bespoke designs, the input required is usually greater. For a typical extension or refurbishment project, you could expect fees to be in the region of:

• Up to £100,000 @ 14%

• £100k - 250k @ 12%

• £250k - 500k @ 10%

• £500k - £1M @ 7.5%

New residential buildings:

When designing new buildings, on open sites, there is often opportunity for greater efficiency and repetition to streamline the required level of input. A new build residential building may see estimated fees as: 

• Up to £100,000 @ 9.5%

• £100k - 250k @ 8.5%

• £250k - 500k @ 8%

• £500k - £1M @ 7.5%

Project complexity influence:

Factors which will lead to increased fees owing to the more resource intensive nature may include:

• Basements

• Listed Building consent

• Restoration

• Specific construction methods

• Site specific complexities

RIBA work stages:

One of the most significant factors influencing architects fees is how much of their input you require. Architects fees are generally split by stages or key milestones. This will allow clients to understand the fee to reach a certain stage and help budget through the duration of the project. The 'stages' of any project have been defined by The Royal Institute of British Architects (RIBA).

Your architects role through these stages are expanded on in our article on project process →

Whilst architects fees are usually based on a full service (RIBA stages 1-6), some clients may only want their architect up to planning for example (RIBA stages 1-3). An indicative percentage split of the fee to respective stages:

• Concept Design (RIBA stage 2) = 15%

• Spatial Coordination (RIBA stage 3) = 20%

• Technical Design (RIBA stage 4) = 40%

• Construction (RIBA stage 5) = 20%

• Handover (RIBA stage 6) = 5%

Up to Planning submission (RIBA stages 1-3)

This can be particularly useful where a client doesn't intend to stay in the property or if the application is being prepared to add value with a view to sell.

This service reflects approximately 35% of the overall fee. On a residential extension project with an anticipated construction cost of £100,000 excluding VAT at a percentage rate of 14%, the planning fee may be in the region of £4,900 excluding VAT.

Up to Building Control (RIBA stages 1-4)

The requirement of a Building Control application is expanded on below. Your architect can work with you to provide the information you need to manage this process ahead of starting construction.

This service reflects approximately 75% of the overall fee. On a residential extension project with an estimated construction cost of £180,000 excluding VAT at a percentage rate of 12%, the fee may be in the region of £16,200 excluding VAT.

Other professional fees:

On a typical residential project, your architect will lead you through the process but you will likely need a few other professionals to support you. An indication of their role and professional fees below;

Structural Engineer:

A Structural Engineer is required to calculate the requirement and size of new structure including foundations, floor slabs, steelwork and other structural elements. This information is required for your contractor and as part of the Building Control process.

Building Control Inspector:

A Building Control Inspector is required to confirm that the design and construction are compliant with Building Regulations. This includes structure, drainage, insulation and ventilation amongst other technical considerations. They will visit site at key milestones to confirm these elements have been installed correctly and issue a 'final certificate' on completion as confirmation.

We are happy to request a fee for these additional services as required and have trusted partners with which we regularly work.

Do I need a Quantity Surveyor?

Whilst your architect may help provide general advice on construction costs, a quantity surveyor specialises in estimating construction costs on an itemised basis. Their findings often act as a guide to adjust the design or act as a benchmark when tendering the project to bulding contractors. Where project budgets are upwards of £100,000, we often advise that we engage a quantity surveyor to price the project accurately.

When do you need a Landscape Architect?

A quick word of advice, whilst a landscape architect is less relevant if you're planning a loft conversion, many properties are set within a terrace with one way in and one way out. With that in mind, you really don't want to be leaving landscaping the rear garden until the new oak floor boards are in. If you want the main contractor to help lay paving and build planters, our advice would be to negotiate this work before appointing them to ensure competitive prices.