Professional Fees – Bespoke Projects @ Rotunda Roundhouses – Unique Garden Rooms & Yurt Style Eco-Buildings

Are you looking to create a new-build, home extension or bespoke modular building in your garden or on your land?

When it comes to commissioning your bespoke project there is nothing more exciting than designing your dream space, to the very last detail.   A ‘Grand Designs’ Dream in reality, you can be your own architect, designer and envision your space…. With the help and guidance of the right professionals of course! But therein lies a plethora of hidden costs and regulatory hoops which you are required to acknowledge.   

Hopefully this blog will break down some of the core costs associated with such a project and highlight the best direction to take as you embark on your bespoke build journey. 

Garden buildings come in one of two forms:

  1. Off the peg  standard range of sizes.  Available usually within 6-12 weeks and one or two elements are customisable to a point
  2. Bespoke  Designed around the clients ‘wish-list’, highly customisable features & non-standard finishes 

The first option may suit you if:

  • You are short on time and need something which has already been designed, tested and certified and is ready to go!
  • You do not require planning permission and you just need a turnkey option to arrive in your garden with minimal work required by you
  • You would like to stick to a set budget and avoid the risk of any surprises where the final bill is concerned
  • You are happy to allow the manufacturers to dictate the design elements and you can work around their specification

The second option is more suited to you if:

  • You have specific requirements/design aspirations that you would like to achieve
  • You would prefer to specify the materials and the finishes yourself
  • There are elements to the building which are ‘out of the norm’ such as linking it to an existing building
  • You enjoy design and creative work and wish to dictate the shape/scale and orientation of the building
  • You are a stickler for detail and would like to source bespoke fittings/ironmongery/sky lights and finishes
  • You like to browse design sites such as Pinterest and incorporate design schemes within your building

What are the cost implications for bespoke buildings?

Briefing requirements will vary from project to project depending on scale and specific design requirements. 

We take time to understand your specific needs, your property wish-list, material requirements and building orientation. We work with our customers to design, build and manage the project from start to completion, to your style and budget.  

The steps required to embark on your bespoke modular building: 

    1. We offer an initial FREE consultation at our Design Studio & Rotunda HQ or site survey at your property, where we take a brief from you and spend time to understand your project, needs, budget and timeline.   (If you are unable to make it into our facility, we can meet via Skype)

  1. We outline the core elements of your design scheme and discuss orientation, finishes and construction style
  2. By the end of the session we undertake a review and provide you with a simple floor plan sketch and a guideline estimate for your project



An Architect or Designer undertakes a more in-depth analysis of your basic design concepts and converts these into:

  1. 3D design sketches & mood boards (if specified) 


2.  AutoCAD plans and Elevations

Architects Drawings For Planning Application Purposes

  • <circa £800.00 ex VAT for small buildings <100m2
  • >circa £950.00 ex VAT for buildings >100m2


We can provide you with all of the architects drawings for local authority Buildings Control applications, and we can assist you with processing of approval documentation in collaboration with local councils and statutory bodies.

We fully specify and provide a fixed cost for the build and delivery, and packages, if any have been selected.


To include Application Management & Buildings Control Liaison through to approval >£2,400.00 



Following Design, Contract, Approvals and Costing stages we start off-site manufacture and on-site preparation works, including (if specified) foundations in readiness for delivery.

We then arrange access, delivery and placement of your bespoke modular garden building and liaise with you to organise the connection to services and final completion.

If you have selected any bolt-on packages like kitchens and bathrooms these are also delivered and completed as part of the final on-site stages.


  • Initial design service and ballpark quotation £ FREE
  • 3D Concept drawings £350.00 ex VAT
  • Mood Boards/ Interior design and bespoke materials £390.00 ex VAT per board 
  • Architects Basic Design Drawings for Planning inc. Site and Location Plans £650.00 – £1,250.00 (dependent on complexity of design)
  • Architects Detailed Drawings for Buildings Control £650.00 – £750.00 (dependent on complexity of design)
  • Buildings Control Application Management & Liaison to approval >£1,900.00 
  • Structural Engineers Calculations >£1,900.00 – £2,500.00 

  • Building Deposit (25%) 
  • Commence Manufacture (25%)
  • Commencement of build on site (40%) 
  • Completion / Defects liability (10%)

To use the example above, excluding third party / Local Authority fees and Planning consultants fees you may need to budget between £5,450 – £6,500.00 to design your Bespoke Modular Building.

Professional services fees are not applicable on ‘off the peg’ buildings as manufacturers have already soaked these costs into their R&D for the product when it was initially designed. 

The fees we’ve cited are applicable to our pricing structure only and you may find that other contractors fees may vary from ours. It could be more economical to enlist the services of a local architect to design your dream bespoke modular building with you and take you through the planning process independently.   We can then manufacture to your design once you have undertaken the design work and are satisfied that your concept is feasible and meets regulatory approval.