One of the most common questions to pop up in our inbox is 'how much does a granny annexe cost?'. As a buyers guide, we can only offer readers a price range, pointing them to specialist companies for more information. As a guide, you are looking at £1,500 to £2,500 per square meter, with the proviso that the cost is affected by the specification choices, site conditions and work involved in connecting to the mains supply.
Annexes Spaces have added a new resource to their specialist living annexe website, which we can point people too. They have created price guides for different sizes and specification of living annexe. They are an excellent place to get an overview of how your specification choices will affect the final cost.
Turnkey prices
What stands out to us is how much is included in the base price of the Annexe Spaces building. Often we see prices for the structure plus foundation, plus kitchen etc, etc. Each annexe example has a pricing table that shows what is included in the example price - including the kitchen and shower room!
They have priced out four popular granny annexe sizes:
- 20m² granny annexe priced from £40,000 inc VAT
- 30m² granny annexe priced from £51,600 inc VAT
- 40m² granny annexe priced from £62,900 inc VAT
- 50m² granny annexe priced from £75,800 inc VAT
Groundworks clearly priced too
When buying a granny annexe type building, the groundworks usually are priced separately to the building. This is because they are dependant on the site conditions, the distance the annexe is from the main house etc. It is hard to even find a guide price for the groundworks for a granny annexe, until now!
Scroll down to the blue tabs towards the bottom of each price guide, and you will see a 'Site Specific Costs' tab. Here, Annexe Spaces have given us a useful guide to budget for the groundworks:
- Armoured cable (for the electrical connection) £25 per meter
- Trenching for water and waste connections £110 per meter
- Skips for building waste, positioned off-road £350 per skip
Layout examples
Along with each price example, Annexe Spaces have created a suggested layout for each size of annexe. You decide the internal layout with the Annexe Spaces designers, but the suggested plans are a good starting point and really maximise the space available.
It is interesting, even with the smaller 20m² example, that Annexe Spaces have configured the space to have a proper bedroom. Often annexes of this size are laid out as open plan studio spaces, so this is a clever use of space. The example 50m² granny annexe layout features two bedrooms.
Request a brochure and site visit
You can request the Annexe Spaces brochure here, but the best way to get an idea of your granny annexe options, and the costs involved for your specific project is to request a free, no-obligation site survey by the Annexe Spaces team. You can do this by giving them a ring on 0845 387 9 387 or by filling in this form, and they will get back to you.