Cracks need context, not an instant label
Fine cracks in plaster are common. Pay closer attention when cracks are new, widening, diagonal around doors or windows, visible through the masonry outside, or accompanied by sticking openings and uneven floors. Photograph the location and ask what has changed rather than deciding from appearance alone that the house has subsidence.
Extensions often crack where new work meets the original building. That may be limited movement at the junction, but it still deserves inspection. Ask for drawings, approvals, engineer's reports and any earlier monitoring or repairs.
Fresh work is not automatically suspicious. New windows, plaster or paving may be genuine improvement. Ask when it was done, who carried it out and whether the work altered ventilation, drainage or structural support. The answer helps the surveyor judge what is now concealed.
Read roof clues from several places
Outside, look for slipped tiles, uneven ridges, damaged flashing and gutters that sag or stain the wall below. Inside the loft, daylight can sometimes be visible through a defect, although felt may hide the roof covering. Dark timbers or stored buckets deserve a question.
A dry loft on viewing day does not rule out a leak that appears in driving rain. Stains on ceilings, especially below valleys, chimneys and flat roofs, should be shown to the surveyor. Ask about the age and material of any flat-roof covering.
Damp low down is not automatically rising damp
Damaged lower plaster, salts and decayed skirting can occur with rising damp, but leaking pipes, high outside paving, blocked cavities and poor sub-floor ventilation can produce similar symptoms. Dark surface mould behind furniture points more towards cold surfaces and humid air, though two problems can exist together.
Notice whether staining is local or spread along a wall, whether it worsens after rain and what lies outside or below it. A handheld meter pressed against plaster does not establish the water source because salts and other materials can affect the reading.
Chimney breasts can show staining from rain, condensation in an unused flue or salts left by years of combustion. A mark near the floor does not identify the source. Ask whether the chimney is used and what maintenance has been carried out above.
Floors and timber deserve attention
Walk normally and notice movement, slopes and soft areas. Suspended timber floors may bounce a little, but a local dip near a wall, bath or external door could justify closer inspection. Carpets and laminate can hide boards, so ask what lies beneath and whether any floor has been replaced.
Look at accessible cellar or sub-floor ventilation. Air bricks blocked by paving or soil can leave a timber void poorly ventilated. Do not assume that stained timber is rotten; its condition and moisture need checking properly.
Drainage and outside water cause expensive confusion
Look for leaking downpipes, overflowing gullies, sunken paving and drains close to extensions or cracked walls. A drain defect can wash soil from beside foundations or keep walls wet. Musty smells and repeated blockage history are worth raising with the surveyor and solicitor.
Check where roofs, patios and sloping drives send rain. Water should not simply collect against the house. If the property has a septic tank, private drainage or shared pipes, establish the arrangement and maintenance responsibility during the legal work.
Make a short location-based list for the surveyor rather than diagnosing each mark yourself. “Rear bedroom ceiling below chimney” is useful. “Roof failure requiring complete replacement” is a conclusion you are not yet in a position to make.
Services may need separate specialists
A normal building survey does not provide a full test of gas, electrics, heating or drainage. If an installation is old, altered or central to your decision, obtain the appropriate specialist report before exchange. Ask the seller for recent certificates, but read what was actually inspected.
Use the survey to decide where further testing is justified. Commissioning every possible test is rarely necessary, while relying on a valuation alone can leave large gaps. Gather enough evidence to judge the property, price and work you may inherit.
Ask the surveyor which defects need watching rather than immediate work. A dated photograph and simple measurement can sometimes show whether a crack or stain is changing while the purchase continues.