Bespoke SIP Garden Room with Hidden Storage in Borehamwood

The structure is based on a footprint of approximately 8m x 3.3m, creating a generous internal garden room alongside a dedicated storage section. The internal layout includes a partitioned storage room approximately 1.5m wide, with the storage area finished in OSB as a practical utility space. The main room remains bright, open and fully finished for everyday use.

This kind of layout works especially well for clients who want one building to do more than one job. The main space can be used as a home office, studio, lounge, hobby room or gym, while the integrated storage area keeps garden equipment, tools or household items tucked away securely without needing a second shed or outbuilding. The drawing pages also show the main room fronted by a central glazed opening and the store accessed via a discreet side/front door arrangement. 

The appearance of this build is one of its strongest features. The front elevation is clad in Western Red Cedar with secret fixings, giving the project a premium natural finish. The sides and rear are clad in cement particle boards and rendered in anthracite grey, chosen both for appearance and because these elevations needed to be fire-resistant due to their relationship to the site boundary.

The building also includes:

• EPDM roof membrane
• Black guttering to the rear
• 400mm canopy above the front doors
• Composite front step
• Anthracite grey external joinery
• Front-facing hidden storage door integrated into the design

Together, these details create a smart, simple and contemporary garden room that looks more like a permanent extension of the home than a standard outbuilding.

the standard foundation approach uses ground screws, offering a practical and cost-effective base for the building. Where ground conditions or project requirements call for a different solution, alternatives such as concrete slabs or concrete pads can also be used.

For the roof, this project is finished with an EPDM rubber membrane, selected for its durability and reliable waterproof protection. Its long lifespan and strong weather resistance make it a well-suited roofing system for modern flat-roof garden rooms.

the building is constructed using Structural Insulated Panels (SIPs) for the base, walls and roof. SIP construction is one of the key reasons this project offers a much higher standard than many basic timber garden buildings. According to the materials section in the document, SIPs use an insulating core bonded between structural boards, creating a building system that is strong, efficient and suitable for long-term use.

For the client, that means a garden room that is:

• Better insulated for year-round comfort
• Faster to install than many traditional methods
• Structurally strong and engineered
• More suitable for regular everyday use

This is the kind of construction approach that makes a real difference when a garden room needs to feel like proper usable space rather than just a summer building.

A standout feature of this project is the inclusion of an LG air conditioning unit with smart internet control. This adds another level of comfort and flexibility to the building, helping regulate temperature throughout the year and making the garden room much more suitable for regular long-term use.

For clients planning to use a garden room as an office, studio or hobby room, climate control can make a major difference to comfort in both summer and winter.

Inside, the garden room is specified to be fully finished and ready to use. The quotation includes:

• Plasterboard and skim finish
• White Dulux vinyl matt paint to walls and ceilings
• MDF skirting
• Laminate flooring
• LED downlights
• White sockets and switches

The result is a clean, modern interior that can suit a wide range of uses, from working from home to relaxing, training, creating or entertaining.

This project includes a solid electrical package designed for daily use, including:

• 8 internal LED downlights
• 5 double sockets
• 4 external LED lights
• Consumer unit
• 1 storage room light
• Wiring to support the building’s internal and external functions

This makes the space practical from day one and avoids the stripped-back feel of lower-spec garden buildings.

To maximise light into the main room, this project includes:

• 1 set of uPVC French doors, approximately 2030mm high x 1600mm wide
• 2 fixed full-height windows, approximately 800mm x 2030mm high
• Anthracite grey external finish for a modern, clean look

This glazing arrangement gives the front elevation strong symmetry and allows the main room to feel open and usable throughout the year.

Why This Garden Room Works So Well ?

What makes this project especially effective is the balance between appearance and practicality. It delivers:

• A premium cedar-fronted design
• Fire-rated side and rear finishes where needed
• A bright main room with full-height glazing
• Hidden integrated storage
• Full internal finishing
• Lighting, sockets and consumer unit
• Smart air conditioning
• A clean contemporary layout that suits modern homes

It is a strong example of how a bespoke SIP garden room can be designed to look impressive while still solving everyday storage and usability needs.