GROUNDWORKS & FOUNDATIONS
What lies below ground decides how long the build stands
A timber deck that lifts after its first winter, a shed that sinks at one corner, a basement wall that smells musty. The faults show above ground but almost always start below it. So we begin at the other end: what kind of soil are you standing on, where does the water go, and how deep does the foundation need to go so that frost does not move it?
Relut itself builds pier foundations for decks and sheds, formwork for casting, and timber decking and steps at ground level. Larger groundworks, excavation, drainage and cast foundations are carried out by partners with their own machinery, and we coordinate the work. The written quote states who does what and who is responsible for each part. The home visit and the quote are free of charge throughout Stockholm County.
What we can help you with
Six common jobs, and who actually carries them out.
Pier foundation for a deck
We set out, dig the holes, place casting tubes or ready-made piers and line them up level and straight. Depth and number are decided by the ground and the load.
Pier foundation for a shed
A shed, greenhouse or guest cabin on piers. We build the foundation and floor frame so the building stands level, has air underneath and keeps the timber away from the ground.
Formwork before casting
We build formwork for steps, footings, edge beams and smaller slabs. The formwork is braced properly so it holds its dimensions when the concrete pushes against it.
Timber decking and steps
Timber decking at ground level, steps on a slope and timber walkways. Structural timber near the ground is chosen in the right preservative class and separated from the concrete with a damp-proof layer.
Excavation and drainage
Carried out by a partner with an excavator. We coordinate the timing, make sure buried cables and pipes are marked out before digging, and do the carpentry that goes with the job.
Paving and ground surfaces
We coordinate simpler paving, paths and surfaces around the house with partners. We plan levels and falls so that water runs away from the facade.
GOOD TO KNOW
Four things that decide whether the groundwork is done right
The information was checked against official sources in October 2026. Your municipality may have its own provisions in the detailed development plan (detaljplan).
Frost decides the depth of the piers
When frost-susceptible soil freezes, it lifts whatever stands in it. According to TräGuiden, the frost depth in such soil varies from 1.1 metres in Skåne to 2.5 metres in upper Norrland, and silt and till are the most exposed. The protection is to go down to frost-free depth or to insulate the ground around the piers, which according to TräGuiden allows the depth to be reduced. Which solution fits is decided by the soil on your particular plot.
The ground should slope away from the house
Rainwater and meltwater should be led away from the foundation. TräGuiden’s general rule is a slope of at least 1:20 within three metres of the house, in other words 15 centimetres lower three metres out once the backfill has settled. If water stands against the base of the wall, or the downpipes discharge straight down at the foundation, the water ends up where you least want it. That is often the first thing to put right.
Permit for changing the ground level
Within a detailed development plan (detaljplan), a site improvement permit (marklov) is required for excavation or filling that changes the ground level by more than 0.5 metres, unless you are adjusting the ground to the level set in the plan. The change is measured on the part of the plot where you dig or fill, not on the plot as a whole. If the groundwork is part of a building permit, it is assessed there. The plan may also have its own marklov requirements, so ask the building committee (byggnadsnämnden).
Ledningskollen before the first spade goes in
Electricity, fibre, water and drainage lie in the ground, even on your own plot. Ledningskollen.se is run by Post- och telestyrelsen (the Swedish Post and Telecom Authority, PTS) and is free to use. You draw in where you are going to dig, and the owners of the cables and pipes reply with a map or by marking on the ground. The service recommends submitting the request 10–14 days before digging. We put it in the timetable before any machine arrives.
How it works
How a groundwork job works
Three steps from first contact to a price you can decide on.
Tell us what you want to build
Get in touch and describe what is going to stand on the ground, roughly how big it is and what the plot looks like. Photos of the site, a plot map and any information about damp in the basement help us prepare for the visit.
Free home visit
We walk the plot and look at the slope, the soil, exposed bedrock, downpipes and where the water goes. We set out the position and assess whether a machine is needed and, if so, how it can get in.
Written quote
You receive a quote describing the type of foundation, materials, what we carry out ourselves and what our partner does, how excavated material is dealt with and which parts may qualify for the ROT deduction (ROT-avdrag).
What affects the price?
The price is decided by the ground: soil type, bedrock or large boulders, how deep the foundation has to go, whether a machine can get onto the plot and whether excavated material has to be taken away. The ROT deduction (ROT-avdrag) is 30 per cent of the labour cost, up to SEK 50,000 per person per year. Skatteverket (the Swedish Tax Agency) accepts, for example, drainage of a house foundation and a deck built onto the house, but not paving laid directly on the ground, walls or freestanding buildings. You get the price in a written quote.
Book a free home visitWould you rather talk to us directly? Call or email us
Free groundworks & foundations home visit in Stockholm County
Tell us what you want done and we will get back to you. Call, email or fill in the form. The home visit and the quote cost nothing, wherever you live in Stockholm County.
Frequently asked questions
Straight answers about Groundworks & foundations before you decide.
Deep enough that frost cannot lift them, or on ground that is not frost-susceptible. TräGuiden states that the frost depth in frost-susceptible soil varies between 1.1 and 2.5 metres across the country, but free-draining gravel behaves differently from clay and silt, and on bedrock the pier can stand directly on the rock. We assess the soil at the home visit and suggest the depth, the number of piers and whether the ground around them should be insulated.
Yes, within a detailed development plan (detaljplan) you need a site improvement permit (marklov) if the excavation or filling changes the ground level by more than 0.5 metres. Exceptions apply if you are adjusting to the level specified in the plan, or if the groundwork is part of a building permit (bygglov) and is assessed there. The plan may also have its own provisions on marklov. So check with the municipal building committee (byggnadsnämnden) before you order fill material or a machine, and before a new deck or wall is built on the filled ground.
The signs are usually in the basement: damp patches at the bottom of the wall, white salt deposits, paint or render coming loose and a musty smell. Start outside all the same. Check that the ground slopes away from the house and that the downpipes lead the water away, because that is sometimes a large part of the cause. The drainage itself is dug by our partner with a machine. We coordinate and do the carpentry and making good that go with it.
No, not ourselves. Larger groundworks, excavation, drainage and cast foundations are carried out by partners who have the machinery and equipment for it. We build pier foundations for decks and sheds, formwork and timber structures at ground level, and we coordinate the work. The quote states which company carries out each part and who is responsible for it, so you know before you say yes.
Yes, for some. For the ROT deduction (ROT-avdrag), Skatteverket (the Swedish Tax Agency) accepts, among other things, drainage of a house foundation, groundworks for water, drainage and electricity, and a deck built onto the house. The deduction is 30 per cent of the labour cost, up to SEK 50,000 per person per year. You get no deduction for paving laid directly on the ground, walls, fences or freestanding buildings such as sheds. In the quote we separate the parts with and without ROT.
Yes, always do. Electricity, fibre, water and drainage can lie in unexpected places even on your own plot. Ledningskollen.se is free and sends your enquiry to the owners of the cables and pipes, who reply with a map or mark the ground. The service recommends submitting the request 10–14 days before digging. Cables you have laid yourself, for example to a garage or garden lighting, you need to point out to us.
Yes, if the foundation belongs to a building where people spend time. For new buildings the limit value is 200 Bq/m³ in indoor air under Boverket’s regulations, and the same figure is the reference level for existing homes according to Strålsäkerhetsmyndigheten (the Swedish Radiation Safety Authority). Radon from the ground gets in through gaps, so the foundation’s sealing layer and penetrations must be done carefully. For timber decking and open pier foundations for sheds the question rarely arises.
No. The home visit and the quote are free of charge throughout Stockholm County. We walk the plot together with you and look at the soil, slope, drainage and how machines and materials can get in. After the visit you receive a written quote for what you want done. Do get out the plot map and drawings of the house if you have them. Otherwise we measure on site.