Where will the house stand?
The rules differ entirely. On land there is an explicit exemption from the building-permit requirement. On water there is no corresponding exemption, and there the matter is instead decided by where the water lies.
Is there already a one- or two-dwelling house on the plot?
A complementary dwelling must complement an existing building. Without a main building there is nothing to complement, and then the ordinary permit requirement applies.
Is the plot within a detailed development plan?
This decides which measurements apply. If you don't know, the municipality's building office or the municipal web map will tell you — we then calculate on the stricter alternative.
How large is the main building's building area?
The complementary dwelling must have a smaller building area than the building it complements. Building area is the house's footprint on the ground, roughly the outer face of the external walls. A normal villa floor is 80–150 m².
What is already on the plot in the way of sheds and complementary buildings?
Permit-exempt complementary buildings and complementary dwellings share a common allowance. Add up the approximate building area of guest cottages, sheds, carports and the like built without a permit.
How close to the plot boundary will the house stand?
Even an otherwise permit-exempt building becomes permit-required if placed closer than 4.5 metres to the boundary. The neighbour may consent in writing to a closer placement.
Is the plot within one hundred metres of the shoreline?
Shoreline protection applies at the sea, lakes and watercourses and covers both land and water. It applies regardless of whether a building permit is required, and regardless of who owns the land. The county administrative board may have extended the zone to three hundred metres.
Is the property in a culturally valuable environment?
The exemption may fall away for particularly valuable buildings and built environments, in areas of national defence interest, and where the municipality has extended the permit requirement in a detailed plan or area regulations. Older archipelago settlement and designated residential areas are typical cases.
What kind of water is it?
This is the single most important question for a placement on water. Some waters have no shoreline protection at all — and then the biggest obstacle disappears entirely.
Was the water constructed after 30 June 1975?
Shoreline protection does not apply at lakes and watercourses constructed after that date. If the answer is yes, the shoreline-protection question disappears entirely — no dispensation needed, no special-reasons examination.
How large is the lake?
Shoreline protection does not apply at lakes whose water surface is one hectare or less — that is, roughly 100 × 100 metres. The county board may however have decided that protection shall apply in the individual case.
Has shoreline protection been lifted in a detailed plan for the site?
The municipality can lift shoreline protection through a provision in a detailed plan. In planned harbour, quay and shipyard areas this is often already done — it is where all existing Swedish floating housing projects lie.
What does the plan's use provision allow?
This is the trap that catches the most harbour projects. A lifted shoreline protection can be retained when a plan is replaced — but only if the use is the same. Going from harbour or berth to dwelling is a change of use, and then everything is examined anew.
Do you have rights over the water area?
To carry out water operations, rights over the water are required. Whoever owns the property controls its water, and rights can also be granted by the property owner. An ordinary seasonal berth fee is likely not such a grant — it must appear expressly from the agreement.
Does anything need to be built in the water?
Piling, dredging, a new jetty or new mooring arrangements count as water operations. For a facility under 3,000 m² of bottom area in a water area other than a watercourse, a notification to the supervisory authority is normally enough — but the work may not begin before it is made.
What applies to your placement
Take this to the municipality
This is a preliminary rule check, not an authority decision. The assessment is based on the answers you have given and on the rules as they apply in August 2026. Only the building committee in your municipality can give a binding decision, and the conditions on the individual property are always decisive. Always check with the municipality before you order.
Would you like us to look at the site?
Send the assessment to us and we'll go through the conditions together — free of charge and without commitment. Your answers come along automatically.