Refurbishments & Extensions


If you are thinking of starting a new-build, refurbishment or extension project to create an exceptional, creative and inspiring home, it is important to involve the right people and allow enough time to achieve all your aspirations within your programme and budget.

Our recent project example CALAMANSAC, was a thoughtful and innovative extension of the existing building, allowing inclusive access to all areas and extending the building by nearly 70%. Recently submitted for the AJ Small Buildings Award and presented as an exemplar project at two national architectural exhibitions.

Calamansac Sail Loft

Extension Build Timeframe


Innovation, inspiring and beautiful homes take time to design. Architects need to present you with designs that creatively interpret the potential of your project to deliver value financially, technically and aesthetically. If you can, allow at least six months prior to your ideal start on site date.

The chart shows the timeframe in month generally needed for a substantial residential extension and refurbishment. The time frame assumes submitting for pre-application advice to the council at stage 2 and not starting technical design until planning permission has been achieved.


The brief for your projects needs to contain practical and aspirational requirements. Prepare as much as you can prior to meeting your architect. This will allow your architect to develop sketch designs, visualisations and models and inject your requirements into every detail of the design, for example some key questions could be:

    • What are your key requirements and project wishes? This could be prescriptive minimum areas and room types or more general types of spaces
    • What doesn’t work about your home as it is? This is often key to understanding how you want to live
    • What is your overall project budget?
    • Are there any time or client constraints?
    • What is the feel of your home that you are aiming for through the refurbishment or extension? Gather images or projects by starting a scrap book for inspiration e.g. a project specific Pinterest board similar to one of ours: Include interior and exterior inspirational ideas.
    • Order your wishlist in a priority order.
    • Gather existing information on the site. This might be any existing drawings or information on previous building work. If there are any restrictions e.g. easements or known service routes
Architectural Project Brief
Budget for Architectural Services


The construction cost is different to the total project cost. Have a clear idea of your maximum overall project budget. Your architect can help you plan your budget. This should include provisions for:

CONSTRUCTION COST – this is the cost the builder will charge you for your works, excluding VAT. Payments are usually monthly with a portion retained for post completion works.

PROFESSIONAL FEES – these cover the fees for the architect, structural engineer, services engineer and cost consultant. Not all these may be needed, but these are the most common.

SITE SURVEYS – e.g. measured building survey, geotechnical and drainage surveys.

VAT – refurbishments and extensions are subject to VAT. Listed buildings and Change of Use/ number of residential units are at a reduced rate. Make sure you allow for the correct rate

STATUTORY FEES – Planning application fees, Building Control fees and potentially heritage or conservation officer reviews.

PARTY WALL OR BOUNDARY AWARDS – if you are building up to or close to a neighbouring wall or floor you will likely need a Party Wall Award.

CONTINGENCY – allow for 10% contingency

A quoted rule of thumb is to allow at least 1/3 of your budget to cover professional and statutory fees and VAT.