What to Look for When Buying a House: Top Features and Red Flags to Consider

The home search can be one of the most exciting and overwhelming stages of the homebuying process, especially for first-time homebuyers. From location and price to structural concerns and potential red flags, there’s a lot to consider. Understanding what to look for when buying a house can help you avoid costly surprises and choose a home that fits your needs.

In this Redfin Real Estate article, we’ll highlight what to look for when buying a house so that you know what questions to ask as you begin the homebuying process. Whether you’re buying a home in Irvine, CA, or a house in Denver, CO, read on to find out the top features and red flags to consider along the way.

1. Foundation and structure issues to look for when buying a house

One of the most critical things to look for when buying a house is the condition of the foundation and structure. If it isn’t solid, even the most beautiful kitchen or spacious backyard won’t matter. Structural issues can affect everything from safety to resale value, and repairs can run into the tens of thousands of dollars. When touring a home, pay close attention to subtle signs of movement or water damage that could signal foundation trouble.

What to look for:

• Cracks in walls or floors: Hairline cracks are usually cosmetic, but wide, stair-step, or horizontal cracks may indicate serious issues.
  
• Uneven floors: Drop a marble or small ball and see if it rolls across the room. Sloping floors often signal settling.
  
• Doors and windows that don’t close properly: If they stick or won’t latch, the home may be shifting unevenly.
  
• Water pooling around the foundation: Standing water near the base of the home suggests poor drainage, which can eventually lead to structural damage.

2. Roof condition

Another essential thing to look for when buying a house is the condition and age of the roof. A failing roof doesn’t just mean costly replacement – it can lead to leaks, mold growth, and damage to ceilings and walls inside the home. Since roofs are expensive to replace, it’s important to get a sense of their age and condition early in your search and know what to look for when buying a house.

Buyer’s checklist:

• Age of the roof: Asphalt shingles typically last 20–25 years. Tile, slate, and metal can last much longer but still need inspections.
  
• Visible wear: Look for curling edges, missing shingles, or bald patches.
  
• Signs of leaks: Check attic ceilings for water stains, damp insulation, or mold
  
• Gutters and flashing: Rust, sagging gutters, or missing flashing can allow water to seep inside.

Tip: Ask for maintenance or warranty records – some modern roofing systems come with transferable warranties that may save you thousands if replacement is needed.

3. Plumbing issues to look for when buying a house

Plumbing is one of those hidden systems buyers rarely notice until there’s a problem. Leaks, corrosion, and outdated pipes can lead to water damage and expensive repairs. Even during a short house viewing, there are ways to test whether a home’s plumbing is in good condition.

What to test during a showing:

• Water pressure: Turn on faucets and showers to check for steady, strong flow.
  
• Leaks and moisture: Look under sinks, around toilets, and near the water heater for signs of dampness or mold.
  
• Pipe materials: Copper and PEX are the standard today; galvanized steel is outdated and prone to corrosion.
  
• Water heater age: Most last 8–12 years. Rust, loud popping noises, or inconsistent heating are red flags.
  
• Sewer lines: In homes built before 1980, consider a sewer scope to check for tree root intrusion or collapsed pipes.

4. Electrical systems

Electrical systems are a major safety concern and should be part of your house hunting checklist. An outdated electrical system can be both a safety hazard and an insurance issue. Electrical fires remain one of the most common causes of home damage, so it’s important to confirm the home’s wiring is up to code.

What to look for when buying a house:

• Breaker panel condition: A modern, labeled breaker panel is ideal. Fuse boxes may not meet current safety standards.
  
• Grounded outlets: Two-prong outlets indicate older wiring. Use an outlet tester to confirm grounding.
  
• Signs of overloading: Flickering lights, buzzing switches, or warm outlets may indicate overloaded circuits.
  
• Wiring type: Aluminum or knob-and-tube wiring, common in mid-20th-century homes, can be a fire risk and limit insurance coverage.

Tip: If the home hasn’t had an electrical update in decades, budget for a professional inspection and possible rewiring – often costing $8,000–$15,000.

 

5. HVAC and major systems to look for when buying a house

Heating and cooling systems have a major impact on your comfort and your budget. They’re also one of the most expensive systems to repair or replace. Knowing the condition of the furnace, air conditioner, and ductwork before you buy can save you from costly surprises.

Key questions for sellers:

• How old is the furnace and AC? (15+ years is nearing end-of-life.)
• When was the last professional service performed?
• Does the home heat and cool evenly?
• Are ducts sealed and insulated properly?
• What’s the home’s average energy bill?

Don’t forget to ask about major appliances included in the sale. Energy-efficient models not only reduce bills but may also qualify for tax credits or rebates.

6. Windows, doors, and insulation

Drafty windows and poor insulation can dramatically impact energy bills, making them important features to look for when buying a house. Energy efficiency is more important than ever as utility costs rise. 

What to check:

• Window quality: Double- or triple-pane glass provides better insulation. Condensation between panes signals failed seals.
  
• Door fit: Exterior doors should close tightly without gaps or drafts.
  
• Insulation: Attics should have at least 12 inches of insulation. Check crawlspaces and basements, too.
  
• Weather stripping: Worn or missing seals around windows and doors are easy fixes but worth noting.

Tip: Ask for 12 months of utility bills. Spikes in heating or cooling costs can indicate poor insulation or inefficient systems.

7. Signs of water damage and mold to look for when buying a house

Water damage is one of the most expensive issues a homeowner can face, and mold poses health risks that are often hidden behind fresh paint or cosmetic updates.

Red flags:

• Musty odors: Especially in basements, crawlspaces, or bathrooms.
  
• Ceiling or wall stains: Brown or yellow marks usually point to past or ongoing leaks.
  
• Warped or soft floors: Moisture trapped beneath flooring can cause wood to buckle.
  
• Visible mold: Often appears around windows, in corners, or near HVAC vents.

If you notice any of these signs, a professional inspection is strongly recommended. As flooding becomes more common, it’s crucial to understand if your home is in a flood zone. Homes in high-risk flood zones require flood insurance that is not typically included in homeowners insurance. They may also cost more upfront, depending on the flood risk.

8. Pest and rodent problems

Pests like termites, carpenter ants, and rodents can cause serious damage before you even realize they’re there. They can also make the home unsafe and unsanitary.

What to look for when buying a house:

• Termite signs: Mud tubes along foundation walls, hollow-sounding wood, or sagging floors.
• Rodents: Droppings in basements, attics, or pantries.
• Carpenter ants: Small piles of sawdust-like debris near wood trim.
• Entry points: Gaps in siding, vents, or rooflines that allow pests to enter.

Tip: In termite-prone areas, always request a wood-destroying insect inspection as part of your purchase agreement.

 

9. Neighborhood and location factors

A home is more than four walls. The surrounding neighborhood plays a huge role in your quality of life, commute, and even the property’s future value.

Factors to consider when buying a house:

• Noise: Visit at different times of day to check for traffic, train, or nightlife noise.
  
• Commute: Test your daily route during rush hour. Check the walk score to get a sense of how pedestrian-friendly the neighborhood is.
  
• Schools: Even without children, good schools boost resale value.
  
• HOA rules and fees: Check for restrictions on pets, landscaping, or short-term rentals.
  
• Future development: Research city zoning maps and planned projects – an empty lot could soon become a busy retail center.
  
• Climate risk: Homes in floodplains, wildfire zones, or extreme heat areas may face higher insurance premiums – or limited coverage availability.

10. Hidden costs: Insurance and climate risk

One of the most overlooked things to look for when buying a house is the hidden cost of ownership, especially rising insurance premiums. In 2025, insurance premiums have risen dramatically in many states due to climate-related risks.

What to investigate:

• Flood insurance: Required in designated flood zones and often expensive.
• Wildfire coverage: Some insurers are pulling out of high-risk regions altogether.
• Extreme heat: Increases cooling costs and puts stress on HVAC systems.
• Storm damage: Hail and wind-prone regions may see higher premiums.

Tip: Request a home insurance quote on the specific property before making an offer. Rising premiums can quickly turn an “affordable” home into a stretch for your budget.

11. Make sure you’re not buying more house than you can afford

It’s easy to get swept up in square footage, extra bedrooms, or that dream kitchen, but stretching your budget too far can create long-term financial stress. Beyond the purchase price, you’ll need to cover closing costs, moving expenses, and ongoing maintenance. Rising property taxes and insurance premiums in 2025 make this an especially important consideration. Keep in mind that real estate taxes and property taxes aren’t always the same — understanding the difference can help you budget more accurately.

How to stay within budget:

• Factor in monthly costs beyond the mortgage, including utilities, HOA fees, and insurance.
  
• Leave room in your budget for unexpected repairs and maintenance (a good rule of thumb is 1–3% of your home’s value per year).
  
• Use Redfin’s affordability calculator to get a clear sense of how much house you can comfortably afford before you start touring.

Tip: Just because you’re preapproved for a certain amount doesn’t mean you should spend it all. Aim for a home that fits both your needs and your financial comfort zone.

What to look for when buying a house FAQs

What are the biggest red flags when buying a house?

Major foundation cracks, mold, outdated wiring, pest infestations, and homes located in high-risk climate zones that are difficult or impossible to insure.

Should I buy a home that needs repairs?

Cosmetic fixes are usually fine, but major structural issues or system overhauls can quickly outweigh any savings on the purchase price.

How do I know if a house has hidden problems?

Hire a licensed home inspector, and consider specialists for areas like foundations, sewers, or roofs if you see warning signs.

What’s the number one thing to check?

The foundation and roof. They’re the most expensive components to repair and protect everything else in the home.