A self-contained granny annexe cannot automatically be treated as an ordinary garden outbuilding under permitted-development rules. The correct planning route depends on the proposed use, design, location and relationship with the main house. We assess this at the start of the project and can help manage the appropriate planning or approval process.

Our current range starts from approximately £70,000, with prices increasing according to size, layout and specification. Ground conditions, drainage distances, electrical connections, glazing, kitchen and bathroom choices and accessibility requirements can all affect the final price. We provide a detailed quotation after discussing the project and assessing the site.

Our annexes can be provided as complete living accommodation including the insulated structure, windows and doors, internal walls, kitchen, bathroom, electrical installation, heating, flooring and decoration. Foundations and service connections are assessed for each property and clearly detailed in the quotation.

SIP construction allows the structural shell to be assembled much faster than many traditional construction methods. The overall project programme depends on the size of the annexe, specification, planning process, site access and service connections. We provide an expected construction programme before work starts.

Yes. Our granny annexes are designed as comfortable year-round living spaces rather than seasonal garden buildings. High levels of insulation, energy-efficient glazing and appropriate heating or air conditioning can provide a comfortable internal environment throughout the year.

Yes. We can design accessible granny annexes with step-free access, wider doorways, practical circulation space, accessible bathrooms or wet rooms and layouts tailored to the occupant’s mobility requirements. Our Oak Accessible design provides one starting point for this type of project.

Yes. As part of the site assessment we look at suitable routes for electricity, mains water and drainage between the existing property and the proposed annexe. The distance, ground conditions and existing drainage levels are important factors in establishing the most appropriate solution and cost.

We build granny annexes across Hertfordshire, Essex, North London and surrounding areas. If you are unsure whether your property is within our normal working area, contact us with your postcode and we can quickly confirm whether we can visit your site.