Patio Covers
An insulated aluminium roof on posts, flashed into your wall with a real gutter.
$12,000 – $25,000
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Level 4
A real room you use in January
Insulated, high-performance glazing and a heat pump, on its own frost-depth foundation. Permitted and engineered as a true addition to your home.
What you get
- High-performance insulated glazing meeting Washington's U-0.30 requirement
- Insulated roof built to the code minimum for conditioned space
- New frost-depth foundation, or full structural reinforcement of an existing deck
- A ductless mini-split heat pump sized for the room
- Full electrical by a licensed Washington electrical contractor
- Energy-code compliance documentation and efficiency credit worksheet
- Interior finish: insulated walls, flooring, trim and paint
- Stamped engineering, full addition permit and all inspections
Is it right for you?
Choose this if you genuinely want the room in January, or if you want the space to count as finished square footage on an appraisal. It is a real addition to your house, priced and scheduled accordingly. If what you actually want is spring through autumn, a three-season room delivers most of the benefit for roughly half the money.
Why it needs a heat pump
Washington requires additions over 150 square feet to earn energy-efficiency credits. A ductless heat pump earns enough on its own to satisfy that. Without one you are on electric resistance heat and have to find the credits elsewhere — which in practice means triple glazing or replacing equipment in your existing house. The heat pump keeps the whole compliance problem inside the new room.
| Typical investment | $55,000 – $120,000 |
|---|---|
| Build time on site | 3 – 5 weeks |
| Typical total timeline | 20 – 24 weeks |
| Permit required | Yes — full addition |
| Heated | Year-round |
| Comfortable days per year | 365 |
Ranges are typical for Puget Sound projects and depend on size, site access and finish level. Your written quote is a fixed number.
Get a Free EstimateCommon Questions
4-Season Sunrooms FAQ
Why is this so much more than a three-season room?
Because Washington has no middle setting. Once a room is heated it is conditioned space, held to the same standard as the rest of your house: U-0.30 glazing across a structure that is mostly glass, an insulated roof, a real foundation, a heating system and an energy-credit worksheet. It is a house addition that happens to have a lot of windows.
Do we have to install a heat pump?
The code does not say “heat pump” — it says earn the credits. A ductless mini-split is simply the cheapest way to earn them, and the only one that does not involve touching your existing house. If your home already runs on a heat pump, ask us: the primary heating source may already qualify.
Does it add square footage?
Yes. A permitted, heated, insulated addition is finished square footage and appears on an appraisal, which is the main financial argument for building at this level rather than the one below.
How long does the permit take?
A full addition permit runs longer than a patio cover — commonly six to ten weeks in Seattle for a room under 750 square feet, and longer above that or on a parcel with a critical-area overlay. We order materials at submittal rather than approval so the factory build runs alongside the review.
Can you match our existing house?
Frame colour, roof profile, ceiling finish, flooring and trim are all selectable, and we take the roof pitch off your existing roofline wherever the structure allows. A well-built sunroom should read as part of the house, not an attachment.
Also Consider
Other ways to enclose your space
Not sure which level is right? We'll walk the yard with you and tell you honestly what fits your house, your lot and your budget.
Ready to create your enclosure?
Let's bring your vision to life. Schedule a free, no-obligation estimate today.
A more beautiful way to live outside.