Missing downspouts can allow large amounts of water to be directed against your homes foundation walls. Concrete is not water proof and this can allow moisture to enter your home. This can be an expensive repair if moisture enters the finished walls of your basement. Ensure all downspouts are directing water away from your home.
In my experience roof shingles last on an average of 18 to 20 years on the average home. The south side roof shingles will typically deteriorate first as they are in contact with more sunlight than the remaining sides. Curling of shingles is the first sign that they will require replacement. Although there are many shingles which are advertised as 25 or 30 year shingles, it is unusual to see them last more than a couple of extra years when compared to regular shingles.
Renovated basements are usually rampant with electrical issues if the home owner has done the renovations himself. The most commonly found electrical problems are un-secured electrical cables, missing or open junction boxes and double tap connections on breakers or fuses in the main electrical panel. This is always an indication that the home owner has done the work and a licensed electrician should be called in to inspect and repair all the wiring. I will typically recommend that potential buyers ask for an electrical certificate for home which indicates that all wiring has been inspected and passed by licensed electrician.
Any renovation in your home is required to have a building permit. Part of the building permit process is having plumbing, structure, electrical and insulation inspected by your local building officials or electrical authority. When a renovation is done with out taking out a building permit you run the risk of un-seen problems coming back to haunt you and most likely costing a great deal of money to repair.
Regular exterior maintenance of your home can prevent needless costs associated with repairs. Caulking seams in window sills and ensuring mortar is still in place on brick window sills can save a lot of repairs for a couple of dollars. Just caulking your asphalt driveway at joint where it meets your garage can prevent separation and sinking of driveway.
Check your attic hatch and ensure that the seal is performing its job to prevent heat and moisture from entering your attic. Trade people and homeowners frequently go into the attic and disturb the insulation without repairing it when finished. This can cause a huge energy loss which is ongoing until problem is repaired. Once insulation is compacted it is easier to add more insulation than to try and repair existing low areas.