How much do you spend on your office compared with your payroll expense?

It's important to have a good work environment for your employees. Subleasing is a good option when you are starting out but having a space to call your own just feels better.

The cost of office space is highly variable. Things like location, market conditions and services plan a huge roll in the price. It's probably not a good metric to compare it to payroll expenses since that varies wildly as well.

A better rule of thumb would be that each person needs around 250 sq feet or so. This is pretty generous as companies go (typically, you just get an 8 x 5 foot cube) but if you want a good environment that scales nicely, then start there.

Again, pricing is going to be variable, depending on your location. Since you don't need to bring clients in, you can probably get away with a little more of an industrial space.

I would recommend finding a place that's within easy walking distance to restaurants. That's a huge plus for a small, nimble company.

I would highly recommend looking for incentives to businesses willing to lease property in a previously depressed area. Many cities offer these subsides to spur growth. It also just happens to be that these 'depressed areas' are often the cool young hip areas. Good places to look are historic areas in your city that are run down, big businesses tend to shy away from old buildings...

We pay less than 10% of our salaries' worth for a fully serviced office. We have a receptionist, the place gets cleaned and we have furniture, internet and electricity all for the same price.

Think along the lines of www.pbcoffices.com (US West Coast) and ParkOffice.com (Belgium)

Your new space should be in a retail area (shops, restaurants, bars), in the opposite direction of traffic, with good (free?) parking and near quality infrastructure. Once had an office in an area where a T1 could short out under sustained rain due to old wiring. Fun!

Speaking of "fun", while it is nice and does help attract talent, make sure you don't ignore the fundamentals. Find a location that is both well-served and helps establish your company's attitude. Doesn't need to be Class A in looks since you are getting visitors, but it does need that in infrastructure, being a software company.

The flipside is asking the talent where they'd rather be. In some areas devs want to be "downtown", whereas in other areas, they'd prefer "the beach". Are you plugged in enough in your area to be able to ask a lot of devs where they'd like to work?

Also, depending on your own philosophy, have you considered other approaches, like shared/serviced offices, or telework?