Garden Gym Hertfordshire

Creating a garden Office/Gym to free up space and add value to your property

Garden gym studio project

Planning and Design

The first step was to plan and design the gym studio. We considered the size of the garden area, the shape of the building, and the layout of the space. The client gave us a brief of the gym equipment they wanted to include and how they wanted us to arrange it. We planned the project considering the overall space utilisation (seasonal use, noise levels, ventilation, budget).

Preparing the Site

We cleared the area. Removed all plants, rocks, and debris. Levelled the ground and marked out the area to be built on.

Laying the Foundation

The next step was to lay the foundation. We excavated the area at 1m depth, wide enough to accommodate the foundation and the necessary drainage and utility lines. We poured a layer of concrete footings at the bottom of the excavation wider than the foundation walls to provide additional support. We installed rebar in the footings and foundation walls to provide additional strength and stability. Next, we poured the concrete for the foundation walls into the excavation, making sure the concrete was level and smooth. We used a vibrator to remove the air pockets and allowed the concrete to cure for 4 weeks.

To prevent moisture from seeping into the building we added waterproofing membrane to the foundation walls. We also added insulation to help regulate the temperature inside the building and prevent heat loss.

Building the Walls

We used agalite blocks to build the walls of the gym studio and mortar to hold the blocks together, making sure the walls are straight and
level. During the planning stages of the project, we had a consultation with the client regarding the choice of blocks or bricks for the project. We presented the following considerations to the client and helped them make an informed choice:

  • Cost: Agalite blocks are generally less expensive than bricks. They are a better option for projects with a modest budget.
  • Strength: Bricks are generally stronger than agalite blocks. This makes them a better choice for buildings that require a high level of structural integrity and areas with high winds or other extreme weather conditions.
  • Insulation: Agalite blocks are known for their thermal insulation properties which makes them generally better choice for buildings that require good insulation. They were a better option for keeping the gym studio warm in the winter and cool in the summer.
  • Moisture Resistance: Agalite blocks are resistant to moisture making them a better choice for buildings in areas with high humidity or moisture levels.
  • Fire Resistance: Both bricks and agalite blocks are fire resistant.
  • Aesthetics: Bricks are generally considered more aesthetically pleasing than agalite blocks.
  • Ease of use: Breeze blocks are generally easier to work with than bricks, so from a construction point of view, agalite blocks were the better option. This would vary from project to project depending on the skill level of the bricklayers and the size and complexity of the project. In this gym project using agalite blocks was the quicker option compared to bricks because the agalite blocks are larger and lighter therefore, they could be laid more quickly. Additionally, they were used with a thin layer of mortar which also sped up the construction process.

Insulating Walls

We commenced the wall insulation process by applying a polyethylene vapour barrier. This plastic sheeting effectively prevents the transmission of moisture into wall structures.

To further enhance this protection, we utilised Damplas Vapour Control. This system is designed to restrict the movement of warm, moist air from within the building, preventing it from reaching the structure's surfaces. This step considerably improves airtightness and, consequently, the overall insulation of the building.

Next, we installed Celotex 25mm insulation boards. These boards are known for their high performance and energy-saving properties, with a thermal conductivity rating of 0.022W/mK and a A green rating. They're easy to cut into shape and feature aluminium low-emissivity foil facings on both sides. Furthermore, they're environmentally friendly with a low global warming potential, helping to reduce the home's carbon footprint. In the summer, Celotex boards also help keep the heat out, reducing the need for air conditioning. Thus, the installation of these insulation boards brings long-term energy savings, improved comfort, and a more sustainable home environment.

A continuous Damp Proof Course was installed at the base of the walls
(approx. 150mm above ground) using high density polyethylene.

Insulating and Finishing Floor

We opted to use high-performing insulating floorboards of 30mm thickness and levelling latex at 8mm. The thickness of the chosen floor finishing tiles was 6mm.

Creating a moisture barrier was critical, given the high humidity often found in garages. We used Laticrete Hydro Ban, a waterproof, fast-curing liquid membrane, ideal for rooms with high humidity. This membrane provided a solid base for the next layer of insulation.

We then covered the Hydro Ban with 30mm insulating wedi boards. These boards have a blue core made from HCFC-free extruded polystyrene rigid foam, coated with cement and integrated fibre mesh fabric. This design provides further waterproofing and thermal insulation, essential for a comfortable living space.

We levelled the floor with SikaBond PVA+ bonding agent and a layer of Sikafloor latex, which offers low shrinkage and high flexibility and resilience.

Installing the Roof

Once the walls were in place, we installed the roof. For this
type of structure, we chose to construct a flat roof (fall less than 10 degrees). To achieve the required fall, we laid the joists level and used firring strips fixed to the top edge of the joists. By using this method of construction, we ensured that the ceiling within the room remained level. The joists were laid in accordance with the relevant TRADA span table tolerances. As guided by Building Regulations Approved Document Part L, we constructed the flat roof to minimise loss of heat and ensured adequate insulation was provided. For the purpose of this project, we used cold roof construction. This is an adequate method for spaces in which there will not be any cooking or washing, therefore the anticipated utilisation does not create a lot of internal moisture vapour.

We placed 125mm Celotex PIR thermal insulation boards between the ceiling joists above the plasterboard ceiling. We cross ventilated the roof void on both sides with a 30mm continuous ventilation strip at the eves and verge and installed abutment ventilation grills in order to prevent condensation occurring within the roof space. We left a 55mm void between the insulation and the underside of the roof decking to allow adequate ventilation.

Finishing the Interior


We finished the ceiling interior of the gym studio by installing plasterboard with a vapour check, which is designed to prevent moisture from passing through the plasterboard.


We installed 20mm heavy duty gym flooring (allowing for weight up to


We skimmed the room at 3mm skim. To create and maintain a clean and bright space we painted the walls using Dulux Easycare paint which has higher durability, is resistant to stains, and is easily washable with soapy water.

Install Equipment

Finally, we installed the equipment as per customer spec.


In conclusion, this comprehensive garden gym studio project transformed the garden space into a highly functional, aesthetically pleasing, and valuable addition to the property. Our meticulous planning and design process, choice of materials, and construction methods led to the creation of a sturdy, moisture-resistant, and well-insulated structure suitable for year-round use.

Our attention to detail, commitment to using top-quality materials, and adherence to construction best practices have undoubtedly improved the property's overall value. The completion of this project not only resulted in the creation of a custom-built gym studio but also an investment that has tangibly increased the property's market value. Moreover, the project succeeded in transforming a previously under-utilised garden area into a functional space, thereby maximising the property's utility and liveability. As such, this garden gym studio project serves as a perfect testament to the benefits of investing in high-quality garden structures - enhancing property value, functionality, and aesthetic appeal.

Garden Office / Gym - Frequently Asked Questions

What permits do I need to build a garden gym/office?

Building permits can vary depending on your location and the size of the structure. In general, smaller structures may not require a permit. However, it is essential to check with your local planning department or governing body to get accurate information about the building codes and regulations in your area before you begin the project.

How long does it take to build a garden gym/office?

The duration of the project can vary widely based on its complexity, the materials used, weather conditions, and the time it takes to receive necessary permits. However, for a professionally managed project, the build phase often takes anywhere between a few weeks to a few months.

What kind of foundation is required for a garden gym/office?

The foundation type can depend on several factors such as soil type, load-bearing capacity, and the size and design of the structure. A concrete foundation is commonly used for garden gyms/offices to ensure stability, especially if heavy gym equipment or office furniture will be placed inside.

How can I ensure the garden gym/office is well insulated?

The choice of materials significantly affects insulation. Using agalite blocks, or bricks with good thermal insulation properties, along with other insulating materials like Celotex boards for walls and roofs, can help regulate the temperature inside the structure. It's also essential to insulate the floor and add a moisture barrier, particularly in humid climates.

What kind of maintenance is required for a garden gym/office?

Maintenance for a garden gym/office generally includes regular cleaning, checking for and repairing any structural issues, and refreshing the paintwork or other finishes as needed. If the structure is well-built and high-quality materials are used, maintenance should be relatively minimal.

Does a garden gym/office add value to my property?

Yes, a well-constructed garden gym or office can significantly increase the value of your property. It adds functional space and versatility, potentially making your property more attractive to future buyers who are interested in having a dedicated workspace or fitness area at home. It's important to keep in mind that the increase in property value often depends on the quality of the construction and the design of the structure.

Start building your dream home with us today! Contact our expert team for a free consultation, and let's turn your vision into reality.

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