a basement

Creating a basement

Everything you need to know about basement construction

Read our step-by step guide on how to plan and create a basement as either part of your self-build project or an home extension project requiring a basement.

Visualise how a basement fits into your building plot

A basement makes the most of your building plot. Especially on traditionally “hard to build” locations, such as sloping sites. Here you will need extensive excavations to install traditional foundations. Why not install a basement, which is also your foundation?

Carry out a soil survey

Soil conditions are a big unknown when undertaking any construction work, especially when a basement is involved. An Interpretive soil Investigation delivers information on the soil conditions, stability, load bearing capacity and not least, the ground water table. All these elements must be considered when calculating a sustainable basement. It would also be wise to allow for some contingency when costing the ground works, the proverbial “can of worms”.

Involve your chosen basement partner early in the planning phase, their expertise can help save money and time

It is advisable to choose a partner who can show a track record of basement installations. An accomplished partner can help highlight potential problems during the planning phase and provide possible solutions. Mitigating mistakes or retrospective adjustments to your basement will be more cost effective in the long run.

Plan your design efficiently

Before planning your basement, make a list of what you would like to do with the additional space. A plant or storeroom has different building regulations to living space. Your basement should be of watertight construction, eliminating the need for a water management system. How much insulation will be needed? When engaging with precast manufacturers such as Glatthaar, upfront planning is necessary. Once the basement has been designed and gone into production any changes will be costly.

Look for professional advice when planning your basement

Basements are beginning to come back into the Self-Build market - in Victorian times they were the norm. Many architects shy away from basements, as this is not something many of them want to get involved with, even though it is an effective way of utilising the valuable building plot. Ask your chosen partner to consider including one in your design.

Understand the difference between cost and value

When building a basement, you get what you pay for. It is essential that not price, but quality and experience be the factors behind your choice of partner. Correcting any problems at a later stage is costlier than the initial investment, so be sure that your finished basement is eligible for an insurance-backed warranty, not only for the structure, but also against water ingress.

Decide which construction method to use

Shuttered concrete walls: Wooden or metal panels are put in place where the basement walls are located. The gap between the shutters is filled with concrete. When the concrete has dried, generally after 45 days, the shuttering is taken down leaving the basement walls. This method is widely used in the UK, but if not done properly, is prone to leakage which is hard to rectify.

Brick and block construction: The walls are made of brick or cinder blocks. This method of installation has a multitude of joints which increases the risk of leakage. In addition to this, cinder blocks retain water making a damp construction.

Precast concrete panels: Manufactured off site, giving a precision that can’t be delivered with in-situ construction, the installation is quick and easy. There is a higher cost associated with this method, but this is offset by the shorter construction time. This method is not widespread in the UK. The result delivers a high standard product, which if installed properly, delivers a watertight basement.

Glatthaar UK are the leading pre-cast concrete basement installers. We manufacture over 5000 objects a year and have over 40 years’ experience in basement construction. There is little that we have not already seen when it comes to basement construction. Our product and installation are eligible for a 10-year insurance-backed guarantee against water ingress. We deliver a basement system which is designed and manufactured in our own production plants, installed by our own employees, and managed by our own project managers.

For more information about basement solutions, reach out to our experts for some no obligation advice.

Explore the range of details featured in our prefabricated basements

Glatthaar Keller prefabricated basements are individually tailored to your requirements. The right combination of concrete, insulation and drainage elements guarantee a completely waterproof basement. You can find a selection of the various construction components we use for our basements in this 3D model.

Click the ‘start’ button to view the interactive model. Use the scroll wheel on your mouse, or the + or - icons on the edge to zoom in and out of the model. You can zoom into any specific point of the module by clicking on the image or selecting the feature in the key.


1. Exterior basement stairs
2. Window
3. Floor drainage exterior basement stairs
4. Exterior basement door
5. Supporting wall basement stairs
6. Backfill protection
7. Light well
8. Light well drainage
9. External insulation
10. Steel anker
11. External tanking 'AquaSafe' basement waterproofing
12. Exterior wall of basement
13. Starter bars exterior wall of basement
14. Drainage
15. External insulation below ground bearing slab
16. PE sheet
17. Spacers
18. Reinforcement steel
19. In-situ concrete
20. Internal basement wall
21. Empty electrical sockets with empty conduits
22. Concrete frost protection
23. Sumb
24. Side rail
25. Wooden shuttering for on-site windows
26. Retaining wall with supporting feet and frost protection
27. Concrete column
28. Cantilever slab
29. ISO Korb
30. Empty electrical conduits in the basement ceiling
31. Internal concrete stairs
32. Floor drainage


Click on the icons below to find out more about how Glatthaar Keller products can help when planning your self-build home