Improve your home and increase its value with ideas from converting your loft to a garden guest room

extra bedroom garden room by granit architects

Image: Granit Architects

The need for an extra bedroom drives many a house move, whether you have a growing family, need overnight guest accommodation, or require a more multifunctional space that can act as an all-in-one study, guest and hobby room.

But according to Nationwide Building Society, adding an extra bedroom to a two-bedroom house can increase its value by around 11 per cent.

Ask your local estate agent what the likely values are for what you have in mind, whether that’s an attic conversion or something more unusual, such as a garden room.

The higher the value of local house prices, the more you will be able to spend on your conversion and happily recoup all your costs.

Rework your space

extra bedroom in a barbican flat designed by francisco sutherland. Photo by Anton Rodriguez

Image: This bedroom in a flat in Barbican, central London was designed by Francisco Sutherland Architects. The £50,000 oak ‘room within a room’ has a shower and wardrobes below

The front bedroom in a standard Victorian layout is often a full-width space, which can be chopped in two to make a double and a single room. As long as the window alignment makes sense and separate access to each room is possible, this type of internal alternation isn’t subject to planning permission. Expect to pay £2,000- £4,000, including new radiators and electrical sockets.

Should you need a new window, planning permission isn’t necessary if it matches the existing ones, although restrictions may apply if it overlooks your neighbours.

A mezzanine is a clever idea if you’re lucky enough to have some double-height space. It can be left open to maintain a light and airy connection with the room below, but for a bedroom, enclosing it may be better for privacy. Internal glazing is useful if there’s no other source of natural light.

Since a staircase to the upper level will take up room, Simon Graham of Yard Architects suggests space-saving alternating tread designs.

Use the garage

austen house extension by adam knibb architects, photo by martin gardner

Image: Martin Gardner. With no space to extend anywhere else, the owners of this Winchester home looked to Adam Knibb Architects to provide an ingenious timber-clad and glass addition. While building on top of an attached single-storey garage doesn’t sacrifice garden space or attic storage, there are other considerations.

The foundations may be less robust than those for the main house, and single-skin brickwork might not support an upper storey, so commission a surveyor or structural engineer to assess the site. Since the bedroom will be on top of a draughty, unheated room, floor insulation is vital. Planning permission is required, too. A simple addition above the garage will cost from £1,000 per sqm.

You could consider demolishing the garage and building a new side extension, but this will come at a greater cost. Detached garages are also extendable, with the same structural considerations as before. Include an en suite if you don’t want your guests trudging down the driveway in the middle of the night looking for the loo.

It will probably cost less than £10,000 to convert a garage into a bedroom – it’s one of the most cost-effective options – if you don’t mind it being located on the ground floor.

Again, planning permission isn’t required under normal circumstances – i.e. your house isn’t a listed building or in a Conservation Area.

But, as a garage falls well short of Building Regulations for habitable accommodation, it will need to be brought up to standard in terms of insulation, ventilation, fireproofing and structural soundness.

In the attic

extra bedroom in an attic by studio 1 architects

Image: This Mansard loft extension in south London, by Studio 1 Architects cost £60,000 and includes a bedroom and large en-suite. Hidden LED ceiling light strips provide indirect light.

A loft conversion is the most common extension project for good reason. It’s a relatively fuss-free undertaking and, as there are lots of construction companies doing them, prices are competitive. Most lofts can be converted under permitted development if they don’t alter the appearance of the property from the front, and next-door neighbours will also have to give their agreement.

The work should cost from around £1,200 per sqm or £20,000-£60,000, depending on the size and spec of the project, and where you live.

Considerations before you get started include whether your attic is suitable for conversion (you will need a head height of around 2.3m for it to be feasible), and where to site the access staircase.

Above your existing flight is the most space efficient solution, but if that’s not possible, it could start eating into existing bedroom space.

Adding an en suite is a great idea, as it’s an amenity that will add even more value to your home.

Garden guest room

extra bedroom garden room by granit architects

Image: Granit Architects designed this £35,000 garden studio. It’s used as a summer house, but with its shower room and WC can host guests staying over on a sofa bed

The rise of multi-generation living means that self-contained garden rooms are becoming more common.

While a DIY garden room can cost as little as £6,000, to make it liveable you need to add good insulation, double glazing and an en suite.

Controllable electric heating is usually a great option, too, as it’s much cheaper than extending gas pipes.

All this can push up costs to £20,000-£40,000. Garden rooms classed as ‘habitable accommodation’ require planning permission, but as James Willmott, co-founder of garden room company Harrison James explains: ‘That means a kitchen, bathroom and bedroom. If you only have two of the three, you won’t need it.’ However, the building must be less than 2.5m tall.

Have you added an extra room to your home? Tweet us @granddesignsmag or post a comment on our Facebook page



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