List the individual tasks and draw the existing and proposed layouts. Identify structural work, changes to services and finishes separately. Include the intended use of each room. Converting an attic into living rooms can involve more requirements than insulating the roof slopes alone. The designer can use this information to assess the work.

In Poland, the applicable procedure depends on the work, the building and the area affected. Certain alterations to the external envelope and structural members of a single-family house require notification accompanied by design documents. This route is subject to the alteration not increasing the building’s area of impact beyond its plot. Other types of work need to be assessed separately.

Other work may be exempt or may require a permit. Listed buildings and protected areas require a separate check. Drawings may also be needed so that the work can be carried out safely, even where the administrative requirements are limited. Review the technical and procedural aspects together.

Assess the foundations, walls, floors and roof. Look for cracks, deflection, signs of damp and earlier alterations. Old drawings may differ from the actual building. Depending on the scope, you may need to open up parts of the structure, survey the building or commission a specialist assessment. Allow for these costs in the preparatory budget.

Removing a wall or enlarging an opening can change how loads are carried. New floor finishes and equipment can also increase the load on a floor structure. Base the solution on an assessment of this building. A similar alteration elsewhere is no proof of suitability. Plan the sequence of work and any temporary supports.

Check whether the existing roof covering and its substrate can remain in service. If roof windows, solar panels or a change of use for the loft are planned, include them in one design. This avoids opening up newly finished layers a second time. New penetrations require suitable flashings, seals and junctions with the layers on the room side.

Metal tile sheets and trapezoidal steel sheets can reduce the weight of the new covering, but the roof structure still needs to be checked. A roof sandwich panel and a single sheet with separate insulation have different support and detailing requirements. Assess these along with the intended use before substituting one for the other. The quotation should describe the entire assembly proposed for the house.

In small rooms and lofts, compare the thicknesses needed for the same thermal performance. PIR with low thermal conductivity can achieve this in a thinner layer than many other insulation materials. Before insulating from the inside, assess moisture, the existing layers and fire protection requirements.

Pay particular attention to junctions at floors, wall plates, windows and partitions. Continuous insulation and airtight connections can affect performance more than a simple comparison of material samples suggests. Establish the cause of any damp before covering the structure. Finishing over wet components can make subsequent repairs difficult.

Allow for points in the work when the extent of repairs must be confirmed after opening up the structure. The contract should set out how additional work is priced and how changes are approved. Keep a financial reserve and time for decisions. In an occupied house, agree how residents and services will be protected and which rooms may have to be closed temporarily.

Carry out the planned inspections before important components are covered. Retain photographs, product documents and design decisions. At completion, check the requirements for finishing the work and for any change of use. A coordinated technical description and clear procedural requirements help the contractor carry out the work and the owner assess the result.