What Features Should a Delaware County PA Mother-in-Law Suite Have to Maximize Resale Value and Usefulness?

By Ben Hill, Premier Property Sales and Rentals

Almost every in-law suite search I've worked on started with something that had nothing to do with real estate. A parent's health changed. A kid came home after college with a plan to save for a down payment. Somebody's mom is ready to sell the house in Havertown she's lived in for forty years, but not ready to move into a community. The house question comes second.

So the useful question isn't "does this house have an in-law suite?" Listings use that phrase for everything from a finished basement with a half bath to a real apartment over the garage. The useful question is which features actually make the space work for the person living in it, and which ones still pay off when you sell. Here's how I sort that out, including a few things that are specific to Delaware County.

Which in-law suite features matter most for daily life?

A private entrance. This is the one I'd put first. If the only way into the suite is through your kitchen, it's a spare bedroom, and everybody will feel that by month three. A side or rear door gives the person living there some independence and gives you some privacy back.

A full bathroom inside the suite. Not down the hall, not shared with the kids. If the suite is for an aging parent, think about a walk-in or curbless shower instead of a tub, and blocking in the walls for grab bars now even if nobody needs them yet. It's cheap during construction and a real project later.

No stairs, or as few as possible. A beautiful basement suite doesn't help someone who can't do steps. A first-floor bedroom and bath, or a lower level that walks out at grade, is worth more to most multigenerational households than extra square footage. Wider doorways and lever handles instead of knobs round it out.

Its own heat and air. Older parents and twenty-somethings rarely agree on the thermostat. A ductless mini-split for the suite solves that, and it's also the easy fix in a lot of Delco basements and additions that the main system never served well.

Laundry close by. People underestimate this one until they're living it. Carrying laundry up and down two flights through somebody else's living room gets old fast.

Sound separation and parking. Insulation between floors and a spot to park near the suite's door are small things that make a big difference in a twin or a house on a tight lot.

Should an in-law suite in Delaware County PA have a full kitchen?

This is where Delco is different from a lot of what you'll read online. Plenty of national advice says to put in a full kitchen, not a kitchenette. Here, a full second kitchen can change how your township sees the house.

Zoning in Pennsylvania is set by each municipality, and Delaware County has 49 of them. Many local codes define a dwelling unit by its kitchen. Radnor Township's zoning code, for example, defines a dwelling unit as having one kitchen for one family. Add a full second kitchen and a separate entrance and, in a lot of towns, you've created a second dwelling unit on paper, which a single-family zoning district may not allow without approval.

Some townships do have a path for it. Upper Darby covers accessory dwellings in its special exception standards, which means a zoning hearing and a list of conditions: the unit has to be attached to the main house or be a conversion of an existing detached building on the same footprint, the people living in it have to be related by blood, adoption, or marriage to the family in the main house, occupancy is capped at two people, it shares the main house's water and sewer, and it's only allowed with a single-family detached house or a twin.

My advice: call your township's zoning office before you design the kitchen. It's a free call. A kitchenette (sink, under-counter fridge, microwave, no range) is often the practical middle ground, but your township is the one who decides where that line is.

The state may change this. In June 2026 the Pennsylvania House passed HB 2186, which would require municipalities to allow one accessory dwelling unit per residential lot by right, and a companion bill (SB 1346) cleared a Senate committee in July. As I write this, neither is law, and the legislative session ends November 30. If something passes, I'll update this post.

Which features help resale, and which can hurt it?

Most buyers looking at your house down the road won't need an in-law suite. Some will, and they'll pay attention. The rest will see a guest suite, a home office, a playroom, or space for a teenager. The trick is building something that reads well to both groups.

Feature	Daily use	Resale	Delco note
Private entrance	High	Helps, buyers like flexible space	Usually fine on its own
Full bathroom	High	Helps, an extra full bath shows up in every buyer's search	Needs a plumbing permit
First-floor or at-grade access	High	Helps, appeals to buyers planning to age in place	Ranches and walk-out splits do this best
Separate heat and air	High	Neutral to helpful	Mini-splits are common in basements and additions
Kitchenette	Moderate	Neutral, easy to repurpose	Usually the safer choice zoning-wise
Full second kitchen	High	Can hurt if it was never approved	May count as a second dwelling unit; ask the township first
Unpermitted finished space	Same as permitted	Hurts, it can surface at resale	Can come up at the resale use and occupancy inspection

That last row is the one I see cause the most trouble. Many Delco municipalities require a use and occupancy inspection when a house sells, and unpermitted work, especially a second kitchen, is exactly the kind of thing that can come up. Pull the permits. If you're buying a house that already has a suite, ask whether it was permitted before you fall in love with it.

One more resale point: don't over-customize. Grab bar blocking, wider doors, and a curbless shower look like good design to the next buyer. A suite that only makes sense as a separate apartment narrows your buyer pool.

Where do Delco houses with suite potential turn up?

Our housing stock decides a lot of this. Much of Delco is twins and rowhomes, and a basement with a back door looks like an easy suite until you check the ceiling height and the egress. Building codes generally want a proper way out of any bedroom, and an older rowhome basement may need real work to get there.

The houses I like for this are the ones with one-floor living already built in: ranches, split-levels with a lower level at grade, and colonials where a previous owner added a first-floor bedroom and full bath. Springfield and Broomall are two places I'd start, because both have a good mix of ranches, splits, and larger lots where an addition fits. Houses with a true suite don't come up every week, and listings describe them in all sorts of ways ("au pair suite," "first-floor primary," "lower level with full bath"), so it helps to have someone who knows what to look for.

How do you pay for an in-law suite?

This is where my mortgage background earns its keep, because the loan structure can matter as much as the floor plan.

If a parent is moving in and helping with the payment, the cleanest way to count their income is usually to put them on the loan as a co-borrower. Their credit and debts count too, and they're on the hook for the mortgage. Family members can also give money toward the down payment, and lenders have a standard process for documenting a gift.

If the suite is a legal accessory dwelling unit and someone will pay rent for it, some programs now let part of that rent count toward qualifying. Fannie Mae allows rental income from one ADU on a one-unit primary residence, for purchases and limited cash-out refinances, capped at 30 percent of your total qualifying income. FHA made a similar change in 2023, also capped at 30 percent, though FHA won't count ADU rent on a cash-out refinance. Notice the word "legal." Rent from a suite the township never approved won't help you qualify.

If you're adding a suite to a house you already own, the usual options are a cash-out refinance, a home equity loan or line of credit, or a renovation loan based on the finished value. With rates where they are, a lot of people with a low first mortgage would rather leave it alone and borrow against equity. My refinance, renovate, or move guide walks through that math, and my Delaware County mortgage rates guide shows what today's rates do to a payment. A permitted addition can also raise your assessment, so check my Delaware County property tax guide before you budget.

I don't offer or arrange loans, and I don't steer anyone to a particular lender. Talk to two or three, tell each one exactly what you're planning, and compare their Loan Estimates. If you're adding a family member to the deed, or a parent is putting money into the house, bring in a real estate attorney and a tax professional too.

Is an in-law suite the right answer?

Sometimes it isn't, and that's worth saying out loud. If a parent needs more care than the family can give, or wants a social life that doesn't revolve around your kitchen, a community may be the better fit. My guide to senior communities in Delaware County is a good place to start that side of the conversation.

If you're looking for a house that already has a suite, or you own one and want to know whether adding a suite helps your value, I'm glad to talk it through. I'll check the township rules on any house you're serious about before you're in too deep.

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