Planning a renovation or build project can feel overwhelming, especially when you’re unsure about where to start. Do you know which experts—like architects, structural engineers, or consultants—you’ll need to involve? More importantly, have you factored professional fees into your budget?
While these professional fees might seem like an added expense, they’re essential for ensuring your project runs smoothly, giving you the end result you always wanted.
In our latest blog, we break down the important things you need to know about budgeting for professional fees. Breaking down what they include and why they’re so crucial, this guide will help you plan confidently—whether you’re tackling a simple remodel or an ambitious new build. Read our valuable insights below.
Budgeting for professional fees
We advise allowing between 10% and 20% of the construction cost for professional fees depending on the scale of the project. Whilst this might seem like a lot, it’s always worth budgeting more of an allowance at the earliest stages to cover you than running out before the build or project is completed. The professionals we recommend including in your budget include:
- Architect
- Structural engineer
- Specialist consultants (planning, highways, arboriculture, ecology, highways, heritage, etc)
- Surveys (measured survey, ecology survey, tree survey, drainage survey etc)
- Specialist designers (MVHR, Structural waterproofing, etc)
- Planning fee
- Building control fee
- Insurances
It means the money’s there if you need a survey or consultant you hadn’t expected, rather than it eating into your construction pot.
The percentage we recommend budgeting for will depend on the scale and complexity of the project. Project complexity is influenced by the design complexity; the contextual complexity (planning restrictions/ trees/ slope etc) and the target energy performance.
How are HEM’s fees calculated?
Charging the right fee is what allows us to achieve the best results for you. Our fees are affected by three key factors.
- Scale
Ultimately, the size of a project has a direct influence on its cost and our fee. The project size affects how much work we need to produce and the value of the end product.
- Complexity
This is key. A large project with no real complexity may require less work and effort than a small project in a tricky location or with a complex design or material palette. Some aspects of complexity are inherent in the site (topography, planning constraints, existing building etc) other aspects are a choice (design approach, material choices, complexity of form and structure etc).
- Performance
The higher the building performance target, the more work will be required to achieve that performance. It may not need to increase the build cost significantly, but designing a project at a lower cost and higher performance requires up front investment in the design team to make that possible.
Read more on the RIBA website about how architects calculate their fees
How are our fees broken down?
A process that follows the RIBA plan of work.
- Measured survey
Undertaking a desktop study and a measured survey of the existing building, or managing a topographical survey of a site.
- RIBA Stage 1: Preparation & brief
We’ll complete a desktop study to understand any constraints which impact your project. We’ll then clarify your brief & project scope by creating strategic options. This will add significant value to your project.
- RIBA Stages 2: Concept Design
We’ll use your brief to develop a design for your project.
- RIBA Stage 3: Developed Design
This is where we use our expertise to guide your dream design through the planning process.
- RIBA Stage 4: Technical Design
Bringing together the experience of your builder, suppliers & design team we’ll turn your vision into something which can be built cost effectively, safely & with a beautiful end result.
- Principal Designer Duties
Required under Building Regulations Act 2023, Building Safety Act 2022 & CDM Regulations 2015
Cost & fee case studies
Grove House
John and Julie wanted us to replace the existing, poor-quality extensions at the back of their new home in Oakham with something that gave them a better connection to their garden.
Aims
- An architecturally beautiful extension but with simple materials [mid build rate]
- Simple garage conversion [mid remodel rate]
- Building regulations performance [no uplift]
Small extension
- 25m2 remodel + 24m2 extension
- Completion year: 2020
- Building Performance: Building Regulations
- Actual Cost: £1575/m2
- Calculated Cost using 2024 prices: £98,000
- Professional fees budget 2024: £16,700
HEM 2024 fees
Result
Our thoughtful design approach allowed us to save our clients at least £20,000 by keeping the existing kitchen and limiting opening sizes to avoid complicated steelwork.
Ashland Road
Sam and Tamara asked us to upgrade their cramped two-bedroom house into a functional, comfortable and low-energy four-bedroom home for their growing family.
Aims
- An architecturally sensitive extension with an uplift in materials [mid build rate]
- Extensive remodel [mid remodel rate]
- Improved thermal comfort [mid performance]
Extension, Remodel & Retrofit
- 65m2 retrofit + 50m2 extension
- Completion year: 2020
- Building Performance: 84kWh/m2.a
- Actual Cost: £1790/m2
- Calculated Cost using 2024 prices: £253,000
- Professional fees budget 2024: £37,950
HEM 2024 fees
Result
Through a thoughtful design process, along with tender and site support, we created a home that functions beautifully for the family. The retrofit work successfully reduced the annual heating bill by £1,390, even though the house is 50% larger.
Craig Eiddew
Margaret and John asked us to make their bungalow on the West coast of Anglesey warmer, more environmentally friendly & more cost effective to run.
Aims
- A simple refurbishment with simple finishes, uPVC windows & minimal remodel [low remodel rate]
- Improved thermal comfort [mid performance]
Retrofit
- 125m2
- Completion year: 2021
- Building Performance: 65kWh/m2.a
- Actual Cost: £1525/m2
- Calculated Cost using 2024 prices: £205,000
- Professional fees budget 2024: £30,500
HEM 2024 fees
Result
We collaborated with the clients to find the right balance between thermal performance and cost. Without solar, we managed to reduce heating bills by £1,380 per year. With solar, we approached zero energy bills, all while staying within a modest budget.
The Orchard
This new build is Lee and Jaclyn’s dream home. Situated in the small rural village of Brattleby near Lincoln, it is light, spacious, and the perfect setting for Lee and Jaclyn to raise their young family.
Aims
- An architecturally restrained design but with uplifted materials [mid build rate]
- AECB standard thermal performance [high performance]
Energy efficient Home
- 205m2
- Completion year: 2018
- Building Performance: 27kWh/m2.a
- Actual Cost: £1650/m2
- Calculated Cost using 2024 prices: £605,000
- Professional fees budget 2024: £72,420
HEM 2024 fees
Result
The site already had planning approval for a 350m² house, but it was inefficient and lacked charm. By reducing the size to 205m², we saved £239,000 in construction costs and achieved heating bills that were £650 per year lower than those of a typical new build of the same size.
Inspired to start your project?
If you’re looking to start your project with an architect that will keep your project within your budget then contact us today.