CONSTRUCTION

We have spent years researching and developing the construction of our garden rooms, having had extensive input from the best structural engineers, architects and manufacturers in the building industry. Therefore, we know our garden rooms are the best on the market, they exceed building regulation standards, are fully habitable, come with 10 year warranty, and a life expectancy of a minimum of 60 years.

Insulated garden room design

THE IMPORTANCE OF BUILDING REGULATIONS

All our garden rooms are built to exceed building regulations standards.  Should you wish to have an independent inspection, we will coordinate with the building inspector on your behalf and ensure we achieve approval for your garden room. This is particularly important if you want to use your garden room for people to sleep in, as building regulations are required by law.

WHAT ARE BUILDING REGULATIONS?

Building Regulations are a minimum standard for design, construction and alterations to virtually every building. They are developed by the Government and are intended to protect your safety, health and welfare. The regulations are also designed to improve conservation of fuel and power, protect and enhance the environment and promote sustainable development.


KEY AREAS OF A HAWKSBECK GARDEN ROOM CONSTRUCTION

The below cross sections illustrate how Hawksbeck Garden Rooms are built and how we exceed regulations in other areas such as foundations, vapour control layer, breathable membrane, cladding airflow, thermal bridging and fire protection.

STRUCTURAL STRENGTH AND DURABILITY

All Hawksbeck Garden Rooms are designed by architects, then our structural engineer will assess the safety, strength and durability to determine its structural integrity. This will include, where necessary, structural drawing and calculations, which form part of the Building Regulations Application. This is a key component of any building work and we want our clients to be reassured everything has been signed off and built to the highest standards.

Insulated garden office rooms

FOUNDATIONS

We work with building control and our structural engineer to ensure we install the right foundations for your garden room. Taking into account soil conditions, slope of the garden and proximity to trees. We then design foundations that cause the least disruption to your garden, the environment and ensures sign off by a building control inspector.

VAPOUR CONTROL LAYER

All Hawksbeck Garden Rooms use foil-backed plasterboard to act as a vapour barrier.

A vapour barrier is a layer on the inner face of the building which is used to reduce moisture flow into and through the walls, roof or floor. This is to prevent damaging levels of condensation occurring in the fabric of the building which in turn would cause decay in timber.

Best garden room construction

BREATHABLE MEMBRANE

At Hawksbeck we use a high-performance membrane that wraps around the exterior SIPs of the garden room. The breathable membrane sits behind the external cladding and its job is to prevent moisture from entering the main structure of the garden room. It also allows moisture generated within the garden room to escape from the building.

CLADDING AIRFLOW

Timber cladding requires battening to ensure airflow to the cavity. At Hawksbeck we double batten (vertically and horizontally) all our cladding. This ensure the perfect amount of airflow in the cavity which allows moisture to escape.

Garden Room Insulation in Essex

THERMAL BRIDGING

Hawksbeck Garden Rooms are built with SIPs and they have an insulated core which virtually eliminates thermal/cold bridging. This also improves the thermal efficiency of our garden rooms compared to timber frame studs.

Thermal Bridging is the ability of external cold transfer to internal walls which can result in cold spots and damp. A thermal bridge/cold bridge is created when materials that are poor thermal insulators come into contact which allows heat to flow through the path created.


GARDEN ROOM INSULATION

An insulated garden room keeps the garden room cool in the summer and warm in the winter. Without it, you would not be able to use your garden room in extreme weather. And, importantly, only well insulated garden rooms pass building regulation inspections.
We achieve exceptionally well insulated garden rooms by using SIPs, which are structurally insulated panels. SIPs out-perform other building methods in virtually every thermal and structural category because the insulation is a component of the construction of the garden room, rather than added on after the structure is build.
As a consequence, SIPs have exceptional thermal performance and u-values (drastically reducing your heating and energy bills), making a Hawksbeck insulated garden room a truly environmentally friendly option. To illustrate the thermal performance of our super insulated garden rooms, the below table demonstrates the thermal performance of a Hawksbeck garden room.
The numbers are U-values, the lower the U-value the more slowly heat is able to transmit through it and so the better it performs as an insulator. Simply put, the lower the U-value the better insulated the garden room is!
TargetHawksbeck Nationwide competitor
Roofs0.150.150.35
Walls0.180.180.31
Floor0.180.180.23

Target is set by Building Regulations in England for extensions. These values form part of the building regulations application.


FIRE REGULATIONS

Any building within 1 meter of a boundary should be constructed of non-combustible materials. At Hawksbeck we use a Masterboard and Fireproof plasterboard in all our fire applications.

It is important to remember that fire proofing is not just about one individual element that offers a Class A1 fire resistance, it’s about the entire system within a wall buildup.

That’s why at Hawksbeck, in addition to Masterboard and Fireproof plasterboard, our SIPs are made from OSB3 which can achieve up to a 90 minute fire rating, combined with the HBCD in the EPS (Insulation) that takes our Fire Rating to well over 4 hours.

FAQ

At Hawksbeck, we use a range of foundation types including ground screws, piles, and concrete rafts, depending on the specific needs of your site. Each option has its advantages, and we select the most suitable method based on an engineer’s recommendation. This is determined by factors such as soil type, proximity and type of trees, slope of the land, and overall ground stability. Our goal is always to ensure your garden room or annexe is built on a safe, stable, and long-lasting foundation.

At Hawksbeck, we can install a standard garden room in under 2 weeks. Larger or more complex designs may take longer, depending on the size and specifications. We provide a clear and accurate timeframe following a free, no-obligation site survey, ensuring you know exactly what to expect before work begins.

To install a garden room or annexe, the site must be cleared before construction can begin. If needed, Hawksbeck can provide a quote for site clearance as part of your project. During your free site survey, we’ll assess the ground conditions and advise on any additional preparation required to ensure a smooth installation.

Hawksbeck garden rooms are constructed using Structurally Insulated Panels (SIPs), a modern building material that combines strength, insulation, and efficiency.

SIPs consist of an insulating foam core (Expanded Polystyrene, EPS) sandwiched between two structural facings, typically oriented strand board (OSB).

This design offers several advantages:

Hawksbeck’s SIPs are BBA-certified, meeting rigorous UK building standards for structural integrity and thermal performance.

At Hawksbeck, the garden rooms are built using Expanded Polystyrene (EPS) Structurally Insulated Panels (SIPs), which serve both as the insulation and the structural framework of the building. These high-performance panels provide excellent thermal efficiency, creating a well-insulated envelope that keeps the space warm in winter and cool in summer. This allows the garden rooms to be used comfortably all year round, while also meeting or exceeding UK Building Regulation standards.

At Hawksbeck we offer a range of different cladding, and external finishes:

  1. Natural Wood Cladding
    • Typically cedar or Fraké Noir
    • Offers a warm, natural aesthetic
    • Ages beautifully (silvering over time)
    • Or, requires occasional maintenance (e.g. oiling) to maintain colour
  2. Thermally Treated Wood
    • Heat-treated for improved durability and stability
    • More resistant to moisture and insects
    • Lower maintenance than untreated wood
    • Retains natural look with enhanced performance
  3. Composite Cladding
    • Made from a blend of wood fibres, cement, or recycled plastics
    • Highly durable and low maintenance
    • Weather-resistant and colour-stable
    • Available in various colours and finishes
  4. Traditional Brick
    • Matches or complements existing house finishes
    • Extremely durable and low maintenance
    • Offers a classic, solid construction look
    • Ideal for blending with listed or period properties

Each cladding type offers different aesthetic and maintenance profiles, and Hawksbeck allows full customisation to suit your property and planning context (especially in conservation areas or near listed buildings).

At Hawksbeck, every garden room is bespoke, including the roof design. We offer a range of roofing options to suit your style and space, including flat roofs, pitched roofs, and dual-pitched (gable) roofs, all available in a variety of high-quality finishes. During the design process, we’ll help you choose the roof type that best complements your garden, enhances natural light, and meets any local planning requirements. We can clad your room

We offer a range of roof finishes including EPDM rubber, standing seam metal, zinc, tile, slate, and green roofs; all tailored to your design and planning requirements.

At Hawksbeck, every garden room is fully bespoke, including your choice of windows and doors. We offer a wide range of high-quality materials such as uPVC, aluminium, and steel, along with various styles to suit your aesthetic and functional needs. Options include French doors, sliding doors, bifold doors, and Crittall-style glazing for a more architectural look.

All our doors and windows come with modern security features as standard, including multi-point locking systems, toughened safety glass, and high-performance frames, giving you peace of mind whether your space is used as an office, studio, or guest room.

At Hawksbeck, every garden room is fully bespoke, including your choice of flooring. One of the most popular options is luxury vinyl flooring, known for its durability, stylish appearance, and easy maintenance. However, we also regularly install a variety of other high-quality finishes such as tiled floors, engineered wood, cork flooring, and even polished concrete for a sleek, modern look. We’ll help you choose the best flooring option based on how you plan to use the space, your style preferences, and the level of comfort and practicality you need.

Yes, at Hawksbeck, we regularly install plumbing for bars, kitchens, and bathrooms in our garden rooms. These features require water supply and waste connections from the main house, and our team are experts in assessing and installing the necessary services. We handle everything from initial planning to final connection, ensuring your garden room is fully functional and compliant with building regulations.

Hawksbeck Garden Rooms typically starts from around £25,000 for a small, non-plumbed room, but the final price depends on the size, design, specification, and included features such as bathrooms, kitchens, or bespoke finishes.

Each project is completely bespoke, so we provide a detailed quote following a free, no-obligation site survey, where we assess your requirements and discuss your vision. Whether you’re building a small office or a fully equipped annex, we ensure your garden room delivers exceptional value and long-term performance.

Yes – a high-quality, well-designed garden room from Hawksbeck can significantly increase the value of your property. It adds versatile, functional living space without the need for a full home extension, which is highly attractive to potential buyers.

Whether used as a home office, gym, studio, or guest suite, a garden room enhances your property’s appeal and can often provide a strong return on investment. At Hawksbeck, we build to the highest standards using SIPs and premium materials, ensuring your garden room is both a lifestyle upgrade and a long-term asset.

At Hawksbeck, we offer one the most transparent and comprehensive quotes in the industry. Every item is clearly listed with an individual price, so you know exactly what you’re paying for with no hidden costs.

We can provide a complete design and build service, managing every aspect of your garden room and surrounding landscaping. Or, if you prefer, we can simply install the garden room itself. Whether you choose a full-service package or a more tailored approach, your quote can include:

  • Design and planning support
  • Foundations and groundworks
  • Full SIPs construction
  • Cladding, roofing, windows, and doors
  • Electrical wiring and lighting
  • Flooring and heating
  • Internet/data cable installation
  • Optional plumbing, kitchens, or bathrooms
  • Project management and aftercare

Our flexible approach means your quote reflects exactly what you need – no more, no less.

Hawksbeck garden rooms are built using high-quality, durable materials designed for year-round use with minimal maintenance. To keep your garden room in excellent condition, we recommend:

  • Regularly cleaning windows and doors to prevent dirt build-up
  • Wiping down cladding (especially timber) annually to maintain its finish — natural wood may require re-oiling or staining every few years
  • Checking roof gutters to ensure no leaf blockages
  • Maintaining the surrounding area — trimming nearby trees and shrubs to prevent overgrowth

If you’ve opted for low-maintenance finishes like composite cladding, even less upkeep is needed. We also offer aftercare advice and optional maintenance services for long-term peace of mind.

At Hawksbeck, we stand behind the quality of our work with comprehensive, insurance-backed warranties to give you complete peace of mind:

  • A 10-year insurance-backed structural warranty from the Independent Warranty Association (IWA)
  • Independent warranties on all doors and windows, provided by our specialist suppliers/installers
  • Roof warranties backed by the manufacturers, subject to the specific roofing system installed
  • Our composite cladding includes an extended manufacturer’s warranty for added protection
  • Luxury vinyl flooring comes with its own extended warranty for long-lasting performance

For a full breakdown of all applicable warranties and their terms, please don’t hesitate to contact us directly – we’ll be happy to provide the details you need

For A Free Garden Room Site Survey Call Us On 01277 414586