If the home is missing some element you feel you must have (upgraded kitchens and baths, etc).  Be aware that improvements are very expensive. Budget at least 30-50% more of your time and money to any anticipated improvement. In this market tradesmen are both difficult to find and expensive to hire.

 Look at any additions carefully.  If there is an addition at the rear of the property changing the building footprint from a rectangle to an “L” chances are it’s an addition. Many additions were built by homeowners who did not obtain construction permits. Like non-permitted construction in item 1 the results range from pretty good to very bad. Often additions are well built yet poorly integrated with the rest of the house. A common defect is when the addition is built “into the slope”: roof and exterior water is allowed to drain into the crawl space or basement causing moisture and termite damage.

 Has the underfloor area been excavated?  In an effort to increase living space many homeowners looked to the crawl space or dugout basement (the small space used for the furnace, water heater, or laundry). Expanding the underfloor area is tricky. The floor framing has to be temporarily supported while excavations are performed. Digging too close to the foundation walls or floor beam columns and posts can undermine their footings. When excavations are complete the floor beam supports have to be replaced with properly sized, placed, and designed columns and posts. The newly excavated basement floor might intersect the seasonal high water table. Correcting the resulting water and moisture problem can be costly and difficult. Again, results are dependent upon the competency of the persons doing the work.

 Is the floor framing adequate?  Most older or smaller houses were framed with 2x8” floor joists. As the joists age they tend to dry out and shrink loosing some of their strength. When you bounce on your heels in the middle of the room you will feel a trampoline effect; this is normal given the size and age of the wood. Water or termite damaged wood requiring repair is another matter. Check around wet areas; bathrooms, kitchens, laundry, water heaters, for signs of weakness. Cracks in thickset bathroom floor tile, especially around the tub enclosure, are indications of water damage. Look for cracks at wall openings such as doors and windows. If there is some amount of cracking and uneven floors you’re probably O.K., if it seems you’re never quite “level” chances are the house has significant problems.

 Water, water, water.  Poor grading and roof drainage can lead to big problems. Soils should slope away from the house. Is the house the lowest in the area or is it slightly elevated from the surrounding terrain? Are there gutters and are they pitched properly towards the downspouts? Are the downspouts piped away from the house or do they dump right at the foundation wall? Is the crawl space or basement wet? Does the house smell of moisture/mold? Are there moisture stains, mildew, or other signs of persistent moisture at the lower levels of the home? For most homes you will answer yes to some of these questions. When you answer yes to most of them there may be problems.

 Look at the roof.  Older roofs were built for light wood shingles. As fire codes changed and asphalt shingles became standard successive layers of heavy shingles caused the rafters to sag at their midpoint. There should be no more than 3 layers of shingles on a roof. Often these layers and the original wood shingles are removed and plywood roof decking is installed. The 2x4 roof rafters typically need to be braced with struts, commonly called knee braces, at their midpoint. Flashing around roof penetrations and at roof wall unions is often poorly installed.

 Chimneys.  Typically, chimney flues installed before the mid 1930’s were not lined with fired clay. Over time moisture and combustion gases cause the mortar to decay. Venting furnace and water heater exhaust into the chimney aggravates this deterioration. Health, safety, and structural deficiencies arise. Check the mortar joints in the fireplace for sandy, loose mortar. Peer up the flue to see if there are loose bricks.

 Galvanized or steel water piping.  Galvanized piped rusts from the inside causing a loss of water flow. Signs of ageing include: rust particles visible when faucet is used, a drop in water flow when more than one fixture (bathroom/kitchen) is in use, and rust marks at pipe unions. At some point piping will need to be replaced. Usually the horizontal sections are replaced followed by the yard pipe to the street, then the pipe legs to the plumbing fixtures.