When you’re under contract on a new house, it’s easy to fall in love with its potential. But before you linger on cloud nine too long, you’ll need the reality check of a home inspection. During a home inspection, a professionally trained inspector visually and physically evaluates the entire structure, from the foundation all the way up to the roof, looking for potential defects or red flags.

These days, the market moves quickly enough and is competitive enough that some buyers consider waiving the home inspection to make their offer stand out. But think very carefully before doing so: A house is most likely the largest purchase you’ll ever make. The last thing you want to do is invest a ton of money only to find out your new home needs extensive repairs. That’s why a home inspection is so important: A good inspector can spot minor problems before they become major ones, and speak to the quality of construction and maintenance the home has been through. They’ll often share pointers for taking care of your new home as well. Many inspectors even recommend that potential buyers attend the inspection.

So what do home inspectors look for, exactly? Here are the top 6 things an inspector will always check out.

1. Basic safety features

Whether a home is safe to live in is a primary concern for any home inspector, which is why many of the things on the home inspector’s standard checklist are safety items. Things they’re on the lookout for include:

  • Smoke detectors: Does the home have them? Are they installed correctly and in the right places (in or near sleeping areas but not too close to the stove)?
  • Ground fault interrupters: These are the special plugs that protect you from shock in areas where water and electricity are in proximity, such as bathrooms and kitchens.
  • Safety glass: Are the glass features installed near stairs or water (like tubs and showers), made of tempered safety glass?
  • Stairs: Are the steps a uniform, safe height and angle? Are they built to code? Do they have handrails and guardrails correctly installed and in the right places?

2. The foundation and exterior ‘envelope’

No matter how old the home, your inspector will look at the basic “envelope” that shields the structure from weather and water. The inspector will walk the property to check for cracks in the foundation and look at drainage, rain gutters and flashings, and window seals.

He or she will also inspect how the walls and roof intersect. For example, an inspector doesn’t want to see lots of caulk there, because that usually means it’s not properly waterproofed. When done right, waterproofing is part of the home design — not something added after the fact.

3. The roof

An inspector can tell if a roof was constructed properly by a professional, or sloppily by an amateur. They’ll want to make sure your roof is well constructed, isn’t showing signs of age or deterioration and will protect you from the elements. They’ll also check to see that any openings — like a chimney or skylights — are properly sealed, flashed and free of moss growth and debris.

Roofs do need replacement from time to time, which can be an expensive process. As part of their inspection report, an inspector will typically provide an estimate of how many good years the roof has left before you should consider replacing it.

4. Major systems: electrical, plumbing, etc.

The inspector will check out all of your home’s most important interior systems, from electrical and plumbing to heating and air conditioning.

  • Heating and air: How well does the heating and cooling work? Do they serve every area in the home evenly? Is there good airflow in every room? If there’s an air return, is it properly located and sized to serve the house efficiently?
  • Plumbing: The inspector will check to see that the plumbing is in good shape, provides enough water to the house and drains as it should. The last thing you need is leaky pipes letting water into your new home and causing flooding or mold problems. This is also where you find out if you have sufficient water flow and pressure.
  • Electrical: Electricity is an essential for modern life, but it can also be dangerous. An inspector will make sure that your electrical system is safe, provides enough power for the house and is installed and grounded correctly. They’ll also check to make sure there are enough outlets.

5. Ventilation

Dangerous fumes can build up in a house if appliances that run on oil or natural gas, like water heaters for example, aren’t installed and configured the right way. Proper ventilation is crucial. Many of these appliances have safety features built-in, but a good inspector will make sure the safety equipment is correctly enabled.

Besides checking the water heater’s ventilation, the inspector will also check its maximum temperature to make sure your tap water can’t get hot enough to burn anyone. Additionally, he or she will make sure that clothes dryers are properly vented to catch lint and expel hot air, which helps prevent house fires.

6. Signs a specialist is needed

Some areas or conditions might need further examination, often by a pro with specialized equipment. A good inspector will know when to call in the heavy hitters, and may even have a network of specialists they can refer you to.

Fireplaces are one feature that always gets careful evaluation. The inspector wants to see that they vent well and that wood-burning fireplaces don’t have a condition that the National Fire Protection Association would call a hazard. If they see something concerning, your inspector might recommend a fireplace inspector, who will use a specialized camera to scope out the interior of the chimney and flue.

Sewers are another area that calls for extra care, especially in an older house. A septic problem hidden beneath your yard can be one of the most expensive repairs a homeowner must make. If you’re buying a home that has sewer service, consider calling in a specialist to have the whole system (from the main house to the street) videoscoped, or a video inspection that goes through pipes, holes and other areas.

How to find a home inspector

You can find an inspector through the American Society of Home Inspectors (ASHI) or by asking your real estate agent or community members for recommendations. ASHI has a code of ethics and standards of practice that members abide by when conducting inspections, which may help you in finding a qualified home inspector for your needs. You can also search the International Association of Certified Home Inspectors.