A garden house on a sloping site - check out what you need to know
Building a garden house on a sloping site is a challenge, but also a chance to create a unique design that fits in with the natural conditions of your plot. Proper planning will ensure the stability of the structure, the comfort of use and the aesthetic appearance of the building. The key aspects to consider are first and foremost the choice of foundations, the fit of the roof, proper soil protection and remembering to comply with building regulations. In this article you will find a comprehensive guide on how to plan and build a garden house on a slope.
Foundations on sloping ground
A solid foundation is the basis for the stability of a garden house, especially on sloping ground, where uneven ground can lead to the structure settling or leaning. The choice of the right foundation depends on the slope of the plot and the type of soil. In addition to the construction of the foundation itself, it is also important to protect it from dampness and to stabilise the ground to avoid erosion and landslides.
Choosing the right foundation
The choice of foundation should take into account the specifics of the plot and the loads that the house structure will carry. On sloping land, solutions that allow minimal interference with the natural terrain are often used.
1. Point (post) foundation – works well on gentle slopes where there is no need to anchor the structure deeply.Foundation posts placed at key points of the house help to distribute the weight evenly, while limiting interference with the ground. On steep slopes, this cost-effective solution may require additional reinforcement.
2. Driven or screw pile foundation – this solution is recommended if you choose steep terrain where traditional foundations would be difficult. The piles can be easily set into the ground, allowing for quick installation and minimal soil disturbance. In addition, this type of foundation effectively counteracts ‘settlement’ of the structure and improves its stability in the event of ground movement.
3. Slab foundation – ensures that the weight of the structure is evenly distributed and is therefore often used on more uniform soils. However, on sloping ground it requires additional ground preparation such as levelling or reinforcement. It has the advantage of high strength, but is also associated with higher costs and longer construction times.
4. Stepped foundation – this is a solution on moderately sloping surfaces where the ground can be gradually adjusted to the building level. The structure consists of several horizontal foundation steps that adjust to the slope of the ground. This keeps the house stable and distributes its weight evenly.
5. Combined foundation – in some cases, the best solution is to combine different types of foundation, such as point and pile or stepped and slab foundations. This approach allows the construction to be tailored to the individual conditions of the plot, ensuring the best stability while optimising construction costs.
Drainage and damp proofing
Adequate damp-proofing of foundations is crucial to avoid structural settlement and to guard against the damage that water can cause. Sloping land can encourage pooling in the lower parts of the plot, requiring effective drainage and protection systems.
- French drainage – one of the most commonly used foundation drainage methods. It consists of making a layer of gravel in which perforated pipes are placed to drain excess water from the ground. This system effectively prevents moisture from collecting around the foundations and reduces the risk of building settlement.
- Damp-proof membranes – protect the foundation from water saturation. Plastic membranes or bituminous layers are placed around the foundation to insulate it from moisture and limit its penetration into the structure.
- Retaining walls – used on steeper slopes, these help to stabilise the ground and prevent landslides. They can be made of concrete, stone or special prefabricated blocks. Re walls protect the foundation from earth pressure and improve the safety of the entire structure.
Stabilise the ground before construction
Before building a garden house on a sloping site, it is worth taking care to stabilise the ground. Terrain with unstable ground can lead to foundation settlement, structural cracking and an increased risk of erosion.
- Terracing the terrain – involves making stepped platforms in the ground to help distribute loads evenly. This is a solution often used on steeper plots that require gradual levelling.
- Create a natural plant barrier – suitable plants with deep root systems can help stabilise the ground and prevent erosion. Trees, shrubs and ornamental grasses can effectively reduce soil leaching and reinforce the soil structure.
- Geonets and geotextiles – the use of special geotechnical materials to reinforce the soil and prevent soil movement. Geonets are placed under the soil or aggregate layer to increase its load-bearing capacity and prevent settlement.
The right roof shape on sloping ground
Choosing the right shape for the roof of a garden house is extremely important, especially on sloping terrain, where the structure must be adapted to the weather conditions and the shape of the plot. The roof not only protects the inside of the cottage from precipitation, but also affects its aesthetics and functionality.
- Single pitch roof – this is one of the most common solutions on sloping land. The slope of the roof facilitates efficient drainage of rainwater and snow in one direction, which reduces the risk of overloading and damage to the structure. It is also an economical solution as it requires less material compared to a pitched roof.
- Pitched roof – the classic option that provides optimum usable space inside the cottage. Thanks to its symmetrical design, it allows water to drain effectively from both sides, minimising the risk of snow or rain. It is a good choice on moderately sloping plots where both aesthetics and practicality of use are important.
- Flat roof – a modern solution that gives the cottage a minimalist look. However, on a sloping site, it requires adequate drainage systems to prevent water pooling. Flat roofs are particularly suitable for cottages with roof terraces or for structures partially sunk into the slope, where they can provide additional usable space.
Permission to build a cottage on a slope
When planning to build a garden house on a sloping site, it is important to check local building regulations. In Germany, it may be necessary to obtain a permit in some cases, especially if the project involves significant changes to the shape of the plot or if the cottage exceeds certain technical parameters.
A permit may be required in the following cases:
- The garden house exceeds a certain size – depending on the region of Germany, small garden houses can be built without formalities, but larger constructions may require permission from the relevant authorities.
- The development alters the natural lay of the land – if the cottage requires interference with the slope, e.g. excavations, retaining walls or other protections, it may be necessary to notify the local authority of these works.
- It is in a landscape protection zone – in some areas of Germany there are additional regulations regarding the harmonisation of the architecture with the surroundings, which may limit the choice of materials or shape of the structure.
It is advisable to consult the local building authority before you start building to avoid legal problems and additional costs.
Prefabricated garden house or bespoke design?
Prefabricated cottages are prefabricated structures that can be quickly installed on the plot. They are a popular choice due to their lower cost and short lead time.
- Quick assembly – prefabricated elements are delivered to site and assembled in a short time, avoiding lengthy construction work.
- Lower cost – prefabricated structures are often cheaper than custom-built homes because they are produced in larger quantities.
- Less customisation – although various models of prefabricated garden house are available, customisation to specific site conditions is limited.
Bespoke cottage
A custom-designed garden house is a solution for people who want to fully customize the structure to suit their plot and needs.
- Adaptable to the slope of the terrain – a bespoke design allows for the specifics of the slope to be taken into account, which can translate into better stability and functionality of the building.
- Greater freedom in the choice of materials and room layout – the client has a say in every aspect of the construction, allowing them to create a bungalow that is perfectly tailored to their requirements.
What does BHB offer?
BHB specialises in the construction of both prefabricated houses and individual designs. Thanks to a wide selection of constructions, it is possible to find the ideal solution to suit plots of land with different slopes.
Our garden house can be adapted to specific terrain conditions, and for more demanding projects we offer a comprehensive service, including both the design and construction of the foundations and the installation of the entire structure.
Slope house and energy efficiency
The correct positioning of a house on a sloping site can have a positive impact on its energy efficiency. Making good use of natural features can help save energy and increase indoor thermal comfort.
- Natural ground insulation – if the garden house is partially sunk into the slope, the ground can act as natural insulation, helping to maintain a stable temperature. In summer, it reduces excessive heat build-up inside and in winter it minimises heat loss.
- Wind protection – sloping land can provide natural shelter from strong winds. By locating the cottage in a depression in the land, exposure to gusts is reduced, resulting in greater comfort and less heat loss in the colder months.
- Optimum sunlight – a well-chosen location maximises the use of sunlight. If the garden hosue is located on a south-facing slope, the sun’s rays can naturally warm up the interior, reducing the need for additional heating sources. In addition, the use of large glazing on the sunny side helps to increase the amount of light in the rooms.
Summary
A house on a slope requires the right foundation, roof shape and damp-proofing. Both planning the construction and choosing a solution that suits the terrain are key. At BHB, we offer prefabricated cottages and bespoke designs that will work even in challenging terrain. Contact us and find the perfect cottage for you!
FAQ
Is a hillside garden house more expensive to build?
Yes, because of the foundations and ground protection, but there are many cost-saving solutions.
Can I build a cottage without a foundation?
No, sloping terrain requires a solid base.
What plants are worth planting around the construction?
Shrubs and grasses with a strong root system will stabilize the ground.
Does a garden house on a slope require additional insurance?
It is worth considering insurance against landslides or heavy rainfall.
What are ways to minimise the cost of building a slope house?
Choosing a lightweight construction, using point foundations and prefabricated elements can reduce construction costs.
