Ask your architect these questions.

OK then -- time to pick an architect!

Hey Mark - what's your availability like?

So this isn't that big of a deal to an architect? I've never worked with one before... I can't tell if they are sensitive or not about this sort of thing from reading the replies here. :-)

We actually talked about this very thing when Mark started our house design. I have a secondary concept sketch in my "back pocket" should we ever need to expand space later. ;-) Advance planning, it's a good thing! (And so is Mark).

Thanks for the input Holly! I actually love Mark's sense of humor and would work with him in a minute if he'd only come out to CO. I have a feeling we'd get along famously. Or infamously...

Two phases? That's it? No problemo. ;-)

Architects design multiple-stage master-planned communities/family villages/communes, so a simple 2-phase thing should be a piece of cake!

The main things to consider are time, money, planning and HOA.

I planned my house back in 2007 as a two phase build. Started with the first phase in 2010 and with the second phase in December 2017. Time flies, building costs increase (dramatically), regulations change. It’s tougher than I anticipated.

If your HOA permits this, go for it. I've got a detached 3-car garage with a complete apartment above it. It's on it's own electrical meter. The fact that I could rent this out was a huge reason to buy the main home. It really helps with the house and tax payment. Your architect and builder can explain to you the costs involved. But, I suggest you try to do it sooner rather than later. Cost to build never goes down and you never know when the HOA will change their by-laws. Plus, any income that you can derive will go a long way to lowering your cost basis for the entire project. Income property is a great thing. Especially when you can manage it via Zillow, Cozy or VRBO.

Laurie,

This sounds like a reasonable and quite desirable idea. Costs will be a bit higher to do separate buildings but the numerous advantages would outweigh some additional expense.

I would definitely recommend at least a conceptual design for the guest house so you can plan the entire site. You don't want your guests looking in your bathroom window for example. :)

Thanks Mark for the shout out. Laurie, I would love to chat with you about the project.

Master plan and design everything which is truly important. You will be glad you did.

Good luck on your project.

Your first question/statement... building 3000 vs 3300 sf. Don't expect a "linear" or "around $300 per foot" savings when you cut out footage, especially if its cheap space... carpeted bedrooms, etc. unless you also cut expensive space and amenities. Home construction costs consist of a combination of fixed & variable costs, in other words, a three car garage costs the same no matter the size of your home.

Finally a real world use for algebra!

Get a builder involved with the architect early, so the communication of numbers comes across clearly "from the horses mouth". When you're working on high end design, sometimes you, the client, hears "xxx per living space foot" while the builder is looking at expensive exterior spaces and adding them on top. Have you accounted for permitting & connection fees, site construction costs on large parcels such as grading, retaining, long utility and driveway runs? How old are those guestimates? Construction costs are moving rapidly so its best to keep them current.

Jeffrey makes some great points. The smaller you go the more your cost per square foot will go up.

I concur with getting a builder involved early. The pricing feedback as the design progresses is crucial to staying on budget. I have a pretty good idea what things cost but I'm not writing checks for work and materials every month.

Virgil's master plan idea is right on. The placement of the buildings, the interaction between the buildings and the way the common outdoor space is planned will present many opportunities and challenges.

You might also want to read [Virgil's articles[(https://www.houzz.com/discussions/virgils-threads-on-buying-land-designing-and-building-a-custom-home-dsvw-vd~5081649?n=37) about designing and building a home. I have a couple of articles on my website you might find helpful as well. Admittedly I'm not a eloquent as Virgil.

Admittedly I'm not a eloquent as Virgil.

It's all those years as a university professor... :-D

Thank you all for the helpful information. Many good points have been brought up. Now I need to talk to my hubby who really doesn't want to "go through the build process twice, let's just get 'er done." :-) He may have a point, we aren't getting any younger. And as someone upthread pointed out, prices only seem to go up.

Hubby has a point. Construction is disruptive, mobilizing each project has associated expenses and construction costs are escalating quickly in Colorado.

Are you leaning towards a separate guest house or attached. Over the years we've stayed in many an AirBnB. Separation is key for guest and host. You can still do this in an attached unit if it's planned carefully.

I'm looking forward to talking with you. I'm dying to know where this is located. :)

Nice. Winter Park is one of my favorite mountains!