Expansive Estates

One of the most profitable opportunities under the new Middle Housing rules (please come to the May 13th City Council meeting if you have any objections to this) will be the estate form.  I had said you don’t maximize potential with only 6 homes on a larger parcel (see the Large Lot Cottages post), but these are not just ordinary homes.  

It is likely that your large, 3/4 acre lot (formerly zoned R-1) is more than 1/4 mile walk from the perimeter of Downtown, Crossroads, Eastgate, Factoria, Bel-Red, Wilburton, or East Main, and also not within the 1/2 walking distance radius of Link or the current or future RapidRide stops.  Therefore, you’ll have to pay $150,000 for each of the fifth and sixth homes you plan to build on the parcel.  This will subsidize up to two households to live in tiny, tiny affordable units in our urban areas. 

Then you calculate your buildable structure size. At 0.9 FAR for all the large lots in Bellevue, that’s 29,403 sqft, and add at least 1200 sqft for each of the two ADUs you’re allowed. Finally, each of the houses gets 300 sqft for parking and storage, and the homes that have the ADUs would get 600 sqft, which you only have to add about 150 sqft to to enable them to have three-car garages. 

Ignoring the garages for now, that means each house could have 5300 sqft.  I’m deducting 2100 SF from that because I think they should all have 3 car garages.  Then that allows each to have 4,950 sqft of living space and 750 sqft of garage. 

I don’t think you can build them as single family homes, so this will probably be three duplexes, and that should still allow plenty of space for gardening and outdoor entertaining. If we add 4950 and 750 and divide by three floors, you get 1900 sf per level for each house.  The garages are likely to be the only part of the homes that actually touch, so you’d probably get a little more space for the ground-floor ADUs above and beyond 1200 sqft, maybe using the full 1900 sqft on one level, and then allowing the average estate size to be 233 sqft larger. 

You might have 1900 sqft on the ground floor and then some entertaining space on a deck on the second floor that’s about 230 sqft. 

If the footprint is 1900sqft on the ground floor plus 750 sqft of garage, that’s 36.5% lot coverage by structures (good thing the proposed rules for middle housing allow 40% lot coverage). The proposed rules for middle housing would also allow up to 50% impervious surfaces, which might be tight depending on how much driveway space you need to reach all three of your estate duplexes. 

One of the best things about these homes is that they can have super high ceilings since they get 8′ of height that ordinary homes do not. You can divide 38′ by three stories to get 11 foot ceilings even after you have a couple feet for high-grade, very solid construction.

There is also a tree code requirement for middle housing that’s 80% of what is required for single family homes, but since you’re presumably clearing a lot that was almost entirely forested before, you would only need to find 132 tree credits, which might be seventeen 20″ trees or twenty-two 16″ trees, and you can always pay toward the street tree fund if you don’t want to keep the trees on your site. 

Good luck!