Occasionally we have a new construction client who wishes to pay hourly, mainly because they think they will not use our full arsenal of new construction services. We explain this is hardly ever the case, but if they wish to do this, it is fine with us! In most cases, we will make more in fees this way, too. Our hourly fees range from $95 for a Junior Designer to $265 for a Principal Designer, with a few categories in between.
For large scale renovations (typically entire homes), we also characteristically work on hourly fees. I find for remodeling, there are just too many unknown factors, so a flat fee is difficult to set. You either have to pad it for all of the worst case contingencies, or underbid it because the scope continues to creep throughout the project.
As with our flat fees, we require our signed letter of agreement, along with a non-refundable retainer to begin work on our hourly fee projects. We then bill monthly for work completed. With both our flat fee and hourly fee structures, we also charge for purchasing, typically at a markup of 40-50% over our wholesale costs. This is also stipulated in our letter of agreement from the beginning, with clients required to make 80-90% of their furnishing purchases through our firm. We buy wholesale, so this offers our clients very competitive prices and value.
I hope this helps you determining fees for your business! I always love to share what has worked well with our firm. Over the years, we have really seen the pattern of the fees needed to do a successful job for our clients.