Frequently Asked Questions

I am putting an addition on my house. Do I need a stormwater plan?

Yes, if your house addition increases impervious surfaces (e.g., roof, patio, driveway), a stormwater management plan is usually required in Pennsylvania. We design plans tailored to your local municipality’s ordinance—see our Residential projects for examples!

What is an NPDES permit and why do I need one?

The answer below is not all inclusive. Each site is different and other items may be required, but it does provide the highlights.

NPDES stands for National Pollutant Discharge Elimination System.  There are various types of NPDES permits, but the most common type in Land Development and home building is a General NPDES permit. This permit is required by law when there is earth disturbance of one acre or more (including the removal of trees/shrubs).

The basic General Permit package includes Wetland and Stream Delineation, Erosion and Sediment Control Plans, Post Construction Stormwater Management Plans, and Infiltration Testing. All of those items have a written report associated with them.

Why should I get a site analysis?

A site analysis saves you money by revealing if a property—residential or commercial—is worth buying. We assess buildability, constraints, and potential costs upfront, avoiding wasted fees. See how we’ve helped Pittsburgh area clients in our Projects page!”

If I send photos of my house, can you design my yard?

We can’t design your yard from photos alone—great design starts with a site visit and talking through your goals. In the Pittsburgh area, we analyze your property to ensure your vision fits. Ready to plan your space? Contact us!

Does HDC provide survey services?

No, HDC doesn’t offer survey services, but we partner with trusted Pittsburgh area surveyors to get the job done. We then use those surveys to craft your site design—see our Commercial projects for examples!