How much does a garden room cost and are there ways to save?

Wondering how much a garden room costs to build? You are most certainly not alone — the popularity of garden rooms has absolutely soared in the last couple of years. 

Much of this is down to the increase in the number of people now working from home, desperate for garden room ideas that will help them to separate work life from leisure time, as well as find a quiet spot to concentrate, away from the hustle and bustle of everyday life. 

The uncertainty of the housing market of late has also caused many people to think twice about moving right now, instead looking for cost-effective ways to add living space to their existing homes while also increasing value for when they do come to sell. 

While building a garden room is usually (but not always) cheaper than extending your home, they still come at a price and in this article we explore the kind of costs you are likely to face should you decide to take the plunge. We also explain the options for those on a tight budget. 

How much does garden room cost?

As with so many things related to house building and improvement, there is no one simple answer to this due to the fact that there are so many variables.

When creating a garden room or outbuilding, the size, specification, materials and fixtures and fittings you choose will all have a direct effect on what you eventually end up paying for it, as well as the supplier you opt for and what you intend to use your garden room for.

For example, a garden room, fully installed, with heating, electrics and a water supply, along with drainage, is going to cost far more than a simple timber structure that requires DIY construction.

This is where it is really important to think about what you want from your garden room.

If you just want somewhere to sit in the garden, sheltered from the elements, then a basic timber garden room with no heating, electrics or insulation may well do you just fine. If, on the other hand, you are aiming to create something more akin to a living space or annexe, you will need high quality glazing, insulation, a heat source, electrics and water and waste facilities.

Garden rooms on a budget

We'll begin by looking at the cheaper end of the market. If you are happy to spend time constructing and finishing your garden room yourself, and possibly customising it a little to suit your needs, there is no need to spend a fortune.

If, for example, you were to order a garden room from Project Timber, and opted for a standard 8ft x 6ft building made from pressure treated interlocking tongue and groove boards, with an OSB floor and roof, a mineral felt roof covering, were happy with no base or guttering and went for an unpainted finish, you would be looking at prices of around £700, uninstalled.

Of course while this price is incredibly attractive, you will need to bear in mind that you will need to organise foundations, a base, rainwater goods, installation and construction and any other extras. There are no electrics, insulation, heating or lights included in the price either — an important consideration if it is garden office ideas you are after. 

If you were to upgrade your specification slightly, you could choose a 10ft x 6ft room, an 11mm tongue and groove timber floor and roof, more attractive black felt roof tiles, a base for the structure, guttering, tins of paint for the main building and the trim — and expect to pay a still very reasonable £1,546. 

Even by choosing a 12ft x 8ft garden room, with a 28mm tongue and groove floor and an 11mm tongue and roof internal roof finish, a smart rubber roof, guttering, a base and the paint needed to finish the building you would only be looking at costs of £2,347.

If you wanted something with insulation, you could take a look at their range of insulated garden buildings which start at around £3,602 for an 8ft x 6ft building.

What does a fully finished garden room cost?

If you are drawn by the idea of a turnkey garden room that comes complete with everything you need to start enjoying it immediately, no effort required, you are obviously going to be looking at higher costs. 

Green Retreats specialise in designing and building luxury, eco friendly garden rooms, have showrooms you can visit and produce a huge range of garden rooms, from those designed to be used as home cinemas to highly insulated garden offices. 

At the lowest end of their price scale lies the Garden Workshop range, which they describe as their 'blank canvas' product.

For £19,200, you can have a 2m x 2m garden room, fully installed, complete with French doors, a choice of flooring, redwood cladding, insulation, foundations, three double sockets, a plywood wall finish, an opening window, heating and internal and external lighting. You will still need to pay for delivery and electrical connection — but that is all. 

If you were to opt for something from their Annexe range, you would be looking at starting prices of £81,745 for a 3m x 5m building, to include kitchen and bathroom options, full electrics and connection, lighting inside and out, building control approval, foundations, drainage, French doors, a range of window options, garden room planning permission, painting, plastering and redwood cladding. 

Is it cheaper to build a garden room or extend?

Once again, the answer to this all depends on the type of garden room or extension you are building. 

When it comes to extension costs, you can expect to pay between £1,500-£2,500/m2 for a fairly basic single storey extension. This price is based on internal space and you will still need to factor in fitting the space out, planning permission, professional fees and so on. 

"If that sounds rather general — that’s because it is. And that’s all you can expect when you have no detail or idea of what the extension looks like, or what materials you’re going to use, or how it is going to be built (and who’s going to do it)," says Homebuilding & Renovating's Director of Content Michael Holmes.

If you were to opt for the budget, basic style of garden room, you are looking at prices of between approx. £360-£840m2. However, one of the luxury, fully installed garden rooms could cost the same if not more than an extension.