Buying a newly built home means it will be fresh, up-to-date, and free of centuries of cobwebs—but it probably won't be perfect. Either while construction is still underway or after you've moved in, you might notice issues. The minor ones, you can probably live with, like paint splotches where they shouldn't be, or uneven tile grout. Major issues could be another matter—in legal terms, "construction defects." These are likely worth following up on, such as faulty installation of windows or anything else that results in water intrusion.
The trouble is, you might not be able to easily spot every sort of home defect, particularly as your contractor or builder wraps up the job. Some could be located behind finished surfaces, as would be the case with improper or incomplete paper or metal flashing around window and doors, structural framing deficiencies, or poor roof installation. Even a home inspector is not responsible for opening up walls to look for such issues.
Your best bet, before and after moving in, might be to watch for red flags, then hire a professional contractor to investigate further. The contractor can advise you whether the issue is a true construction defect, or can be dealt with through simple repairs or maintenance. (For instance, slight cracks in stucco, siding, or wood trim might be addressed in the normal repainting cycle for your location.)
Below are tips for examining your almost-built or newly built home for signs that its construction was substandard and might contain major defects.
Ideally, you should monitor your home's construction all along the way. If your home is being built by a developer (as part of a planned community), then you should also arrange to conduct a final examination of the home before the closing date. At this time, you can also bring in a professional inspector to identify issues and write up a report. This allows you to raise issues with the builder while you still have maximum leverage.
If a general contractor is building you a custom home, you should ask questions as the work progresses, and make sure to schedule an end-of-construction walk-through. If you do not obtain satisfactory answers to your questions along the way, consider bringing an independently hired contractor to attend the walk-through with you.
If you have already closed on the home purchase, and didn't have a chance to inspect it pre-closing or at the end of construction, it's not too late to take action. In fact, some issues— particularly those to do with water intrusion—might not come to your attention until after you have lived in the house for a while (or at least been through a rainstorm or two).
Let's assume that your home has been finished and that you've moved in. Here are ways to examine the quality of the finished product.
Take a walk around the outside of your newly built home, with camera and notepad in hand. Issues to do with exterior surfaces, sealing of windows and doors, a patio or deck, and concrete surfacing should be your main focus here.
If the your house is surfaced with stucco, look for cracks that are larger than "hairline"—particularly at the corners of windows and doors. Flaking or "spalling" could indicate that the stucco was not applied properly. Look for gaps between the stucco and windows, doors, hose bibs, pipes, ducts, and electrical fixtures. These gaps could be sources of water intrusion.
If the siding is a wood product, look for significant waviness of the boards and (especially if it has rained since the house was built) see whether the ends and edges of the boards appear swollen from moisture intrusion. Inspect wood trim around doors, windows, and other locations to see if joints have opened up or cracks in the wood have developed. These conditions can develop over time.
If you have exterior decks or patios, look for cracks in the walking surfaces and at the intersection between the deck and the wall of the house.
Problems with your roof are more difficult to observe and normally require the assistance of a trained professional. You should not walk on your roof. In fact, if the roof is made of tile, you could void the manufacturer's warranty by doing so. But if you can see portions of your roof from inside, definitely look for loose or missing shingles, or areas that don't seem fully covered.
As you walk around outside, look for cracks in concrete sidewalks, driveways, garage floors, or retaining walls. These could indicate that the soils were not properly prepared or that the concrete structures were not properly installed.
Your next task is to walk around the interior of your home.
Look for water stains around windows and doors on the wood trim or drywall, particularly at the window sills or at the base of exterior doors. Inspect all interior wall and ceiling surfaces for cracks in the drywall, which could indicate soils movement or structural framing problems. (Lesser drywall problems, such as nail pops and tape cracks, can easily be addressed the next time you paint the interior of the home.)
If doors are sticking shut, they might have been installed incorrectly. In the case of bathroom or kitchen doors, if the tops and bottoms were not painted, moisture could be causing the wood to expand.
Check for flooring issues such as: tile cracks; uneven wood floor boards or widening cracks between boards; water stains in carpeting or other flooring at the base of windows, doors, or showers; and discolored or curling linoleum. Some of these problems could result from water infiltrating through cracks in the foundation.
Look for water stains under kitchen sinks.
Check the controls for heating and air conditioning. If they aren't producing the expected hot or cold air, it could indicate problems with your HVAC system. Also plug something small in, to check whether any electrical plugs or switches do not work.
As mentioned, you will probably want to hire a general contractor to give a professional opinion on red-flag type problems and look for others that you might not have noticed.
Your next step depends on whether you have agreed with the builder to notify them and provide an opportunity for repairs. See, for example, New-Home Defects: Holding Your Builder Responsible Under a Warranty.
If you have notified the builder and it hasn't worked, or if the problems seem more serious than mere repairs can address, you might need to pursue legal action. See, for example, Who Can I Sue for New-Home Defects: Architect, Contractors, or Only the Developer? and Is It Too Late to Sue My Home Builder for Construction Defects I Found Years Later?.