From Summerhouse to Cosy Garden Room
Published: 30 August 2026
Reading Time: 3 minutes 10 seconds
A good number of the projects we have featured on the Guide start the same way. An ageing summerhouse comes out, and a fully insulated garden room goes in its place. A summerhouse built from interlocking timber boards is a single-layer structure, with nothing between the inside and the outside but the thickness of the timber, so it holds very little heat in winter. It won't last as long as a garden room either, because it isn't made from the durable materials a garden room is built with.
That was the position in a mature garden in Sheffield, where a summerhouse had occupied the same spot for many years and had seen better days. The owners wanted somewhere they could entertain family and friends whatever the weather. Cosy Garden Rooms removed and disposed of the old building as part of their service, then built a 5m x 4m garden room in its place.
A Multi-Layer Building Made for Year-Round Use
The difference between the two buildings is in how they are put together. The new 20sqm room is a multi-layer insulated structure, wired throughout and fitted with far infrared heating: two 600 watt panels and one 300 watt panel, enough to hold the room at a comfortable temperature through the winter.
The doors and windows are the same specification as those used in a house, rather than the lighter joinery a summerhouse comes with. Streamline anthracite aluminium three-pane bifold doors run along the garden side, with three windows alongside them.
Cladding Chosen for a Mature Garden
The garden is surrounded by established trees, hedges and shrubs and has a very natural feel. The owners wanted the new building to sit comfortably within it, without the maintenance that real timber brings.
Composite cedar slatted cladding covers the front and right elevation, the two sides most on show, giving them a warm, natural appearance against the planting. The left and back are finished in anthracite Hardie® Plank, a fibre cement board that needs no maintenance and costs less than the slatted boards. Putting the premium cladding where it is seen and the maintenance-free board where it isn't is a sensible way for Cosy Garden Rooms' client to spend their budget.
A More Contemporary Take on the Summerhouse Glazing
The glazing picks up the arrangement the summerhouse had and brings it up to date. The bifold doors fold back to open a big section of wall onto the garden, and the views from inside are the same ones the owners had before.
Inside is Cosy Garden Rooms' signature finish: white painted grooved wall boards, a plain white ceiling and light chestnut laminate flooring, creating a light, neutral finish.
From Design to Final Electrical Connection
Cosy Garden Rooms handle the whole project, from the design through to the final electrical connection back to the house, so the room is ready to use on the day it is finished. Here that also covered taking the old summerhouse away and installing the concrete base.
The owners had a family garden party planned and wanted the room ready for it. From removing the summerhouse to completing the garden room took five days.
The new room has slotted into the place the summerhouse was sitting, amongst planting that was already established, and the photographs taken on completion show the care the Cosy Garden Rooms team take on site. The design updates the garden and gives the family a place they can enjoy all year round.
Learn More
Cosy Garden Rooms design and build bespoke insulated garden rooms across much of England, each one tailored around how the space will be used and the garden it sits in. To discuss a project of your own or see more examples of their work, visit www.cosygardenrooms.co.uk, call 0115 77 22 715, or email info@cosygardenrooms.co.uk.
