# Measuring land on a hill side **URL:** \ **Category:** Factual Questions\ **Created:** [August 22, 2014, 4:58pm UTC](https://boards.straightdope.com/t/measuring-land-on-a-hill-side/696215 "2014-08-22T16:58:19Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [August 22, 2014, 4:58pm UTC](https://boards.straightdope.com/t/measuring-land-on-a-hill-side/696215/1 "2014-08-22T16:58:19Z")
Would a hill side be measured by the actual length of the hill or as if the hill were removed and the land was flat? This would be to determine how much land was purchased. ---
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [August 22, 2014, 5:00pm UTC](https://boards.straightdope.com/t/measuring-land-on-a-hill-side/696215/2 "2014-08-22T17:00:06Z")
I wish I could delete this, once I read it the answer is pretty obvious. ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [August 22, 2014, 5:03pm UTC](https://boards.straightdope.com/t/measuring-land-on-a-hill-side/696215/3 "2014-08-22T17:03:55Z")
if you purchased a valley would you have as much land as a mountain? ---
**Author:** ![SeldomSeen](https://avatars.discourse-cdn.com/v4/letter/s/7ba0ec/32.png) [@SeldomSeen](https://boards.straightdope.com/u/SeldomSeen)\ **Post date:** [August 22, 2014, 6:10pm UTC](https://boards.straightdope.com/t/measuring-land-on-a-hill-side/696215/4 "2014-08-22T18:10:01Z")
Well sure. Heck, if you ironed Idaho flat we’d be twice as big as Texas…:rolleyes: ---
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [August 22, 2014, 6:16pm UTC](https://boards.straightdope.com/t/measuring-land-on-a-hill-side/696215/5 "2014-08-22T18:16:35Z")
I was looking at an add for some land and it said 12 acres of avaocado trees. Looking at how hilly the land was in the pictures I started thinking maybe they were measuring the side of the hill. As soon as I made the post I regretted it. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [August 22, 2014, 8:44pm UTC](https://boards.straightdope.com/t/measuring-land-on-a-hill-side/696215/6 "2014-08-22T20:44:49Z")
I’m not sure the answer is obvious. If you measure the land surface area, you get one figure. If you measure it as the area of a polygon on a map, you get a different figure. ---
**Author:** ![chappachula](https://avatars.discourse-cdn.com/v4/letter/c/d2c977/32.png) [@chappachula](https://boards.straightdope.com/u/chappachula)\ **Post date:** [August 22, 2014, 9:04pm UTC](https://boards.straightdope.com/t/measuring-land-on-a-hill-side/696215/7 "2014-08-22T21:04:25Z")
There is only one answer : for all legal documents. the land is measured as if it were flat. If you own a plot of land on a steep hill, you will actually have possession of more square feet than is shown on the map, on the surveyor’s plat,on the property tax assessment, and on all official documents regarding that plot of land. ---
**Author:** ![Ignotus](https://avatars.discourse-cdn.com/v4/letter/i/ecc23a/32.png) [@Ignotus](https://boards.straightdope.com/u/Ignotus)\ **Post date:** [August 22, 2014, 9:39pm UTC](https://boards.straightdope.com/t/measuring-land-on-a-hill-side/696215/8 "2014-08-22T21:39:46Z")
> [@](#): > > chappachula There is only one answer : for all legal documents. the land is measured as if it were flat. > > If you own a plot of land on a steep hill, you will actually have possession of more square feet than is shown on the map, on the surveyor’s plat,on the property tax assessment, and on all official documents regarding that plot of land. I take your word for it, concerning the USA: do you know if this rule is applied internationally? (Google is not my friend.) An interesting question, and maybe a slight hijack: if you own a property, could you legally increase its’ area (and, more importantly, the total solar input on it!) by filling out the land to create a south-facing (assuming it’s located in the northern hemisphere) slope with a steep backside? ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [August 22, 2014, 9:56pm UTC](https://boards.straightdope.com/t/measuring-land-on-a-hill-side/696215/9 "2014-08-22T21:56:01Z")
If the land slopes evenly, it might be fairly easy to calculate the surface area. However, once you have a property that includes ravines, cliffs, or many hills it would become very time consuming to survey it in sufficient detail to calculate the actual surface. As a practical matter, calculating area as if the parcel were flat will be much easier. ---
**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\ **Post date:** [August 22, 2014, 10:50pm UTC](https://boards.straightdope.com/t/measuring-land-on-a-hill-side/696215/10 "2014-08-22T22:50:12Z")
the surface area is the horizontal plane surface area. That is roughly determining how large a building you can build, how much flat land you can make, and for growing crops, how much sun and rain you get. Of course, the very steep land may actually count as nearly zero usable acres per horizontal acre. ---
**Author:** ![GusNSpot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gusnspot/32/436_2.png) [@GusNSpot](https://boards.straightdope.com/u/GusNSpot)\ **Post date:** [August 23, 2014, 4:01am UTC](https://boards.straightdope.com/t/measuring-land-on-a-hill-side/696215/11 "2014-08-23T04:01:34Z")
> [@Colibri](#): > > If the land slopes evenly, it might be fairly easy to calculate the surface area. However, once you have a property that includes ravines, cliffs, or many hills it would become very time consuming to survey it in sufficient detail to calculate the actual surface. As a practical matter, calculating area as if the parcel were flat will be much easier. Hire a mapping company to map it. You can then get information everywhichaway that you could want. Volume, surface area etc. IT works very good and is used on coal piles at power stations etc. to do inventory etc… ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [August 23, 2014, 4:04am UTC](https://boards.straightdope.com/t/measuring-land-on-a-hill-side/696215/12 "2014-08-23T04:04:57Z")
> [@GusNSpot](#): > > Hire a mapping company to map it. You can then get information everywhichaway that you could want. Volume, surface area etc. Of course it can be done if you need it. But most people don’t, and it’s going to be far more expensive than just surveying to figure out the horizontal area. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [August 23, 2014, 2:07pm UTC](https://boards.straightdope.com/t/measuring-land-on-a-hill-side/696215/13 "2014-08-23T14:07:21Z")
> [@](#): > > Quoth **Ignotus** : > > An interesting question, and maybe a slight hijack: if you own a property, could you legally increase its’ area (and, more importantly, the total solar input on it!) by filling out the land to create a south-facing (assuming it’s located in the northern hemisphere) slope with a steep backside? In principle you could, but it would require a slope so extreme that you’d be casting a shadow across your neighbors’ land, which might not be legal. And at any latitude where solar would be worth bothering with at all, it’d take an awfully steep hill even then, which might be too steep to be practical even if you don’t care about your neighbors. ---
**Author:** ![The\_Great\_Unwashed](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/the_great_unwashed/32/4791_2.png) [@The\_Great\_Unwashed](https://boards.straightdope.com/u/The_Great_Unwashed)\ **Post date:** [August 23, 2014, 2:14pm UTC](https://boards.straightdope.com/t/measuring-land-on-a-hill-side/696215/14 "2014-08-23T14:14:50Z")
[Calculating the true area of a plot of land would be as problematic as calculating the true length of a coastline.](http://en.wikipedia.org/wiki/Benoit_Mandelbrot#Fractals_and_the_.22theory_of_roughness.22) ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [August 23, 2014, 3:22pm UTC](https://boards.straightdope.com/t/measuring-land-on-a-hill-side/696215/15 "2014-08-23T15:22:29Z")
> [@Ignotus](#): > > An interesting question, and maybe a slight hijack: if you own a property, could you legally increase its’ area (and, more importantly, the total solar input on it!) by filling out the land to create a south-facing (assuming it’s located in the northern hemisphere) slope with a steep backside? people do the equivalent all the time by putting solar collectors (thermal or electrical) on racks. this is done both on the surface, the tops of buildings or at whatever height you have solar access. ---
**Author:** ![jtur88](https://avatars.discourse-cdn.com/v4/letter/j/e9c0ed/32.png) [@jtur88](https://boards.straightdope.com/u/jtur88)\ **Post date:** [August 23, 2014, 4:10pm UTC](https://boards.straightdope.com/t/measuring-land-on-a-hill-side/696215/16 "2014-08-23T16:10:58Z")
> [@johnpost](#): > > people do the equivalent all the time by putting solar collectors (thermal or electrical) on racks. this is done both on the surface, the tops of buildings or at whatever height you have solar access. You can also sell advertising space on a visible vertical cliff face, without using up any of your “land”. If your cliff has an overhang, you actually own parcels of flat land at two different elevations, both with the same survey coordinates. Which raises the question of whether you can sell one of the parcels and not the other. ---
**Author:** ![GusNSpot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gusnspot/32/436_2.png) [@GusNSpot](https://boards.straightdope.com/u/GusNSpot)\ **Post date:** [August 23, 2014, 8:18pm UTC](https://boards.straightdope.com/t/measuring-land-on-a-hill-side/696215/17 "2014-08-23T20:18:11Z")
> [@The\_Great\_Unwashed](#): > > [Calculating the true area of a plot of land would be as problematic as calculating the true length of a coastline.](http://en.wikipedia.org/wiki/Benoit_Mandelbrot#Fractals_and_the_.22theory_of_roughness.22) Unless you are demanding the actual surface area of small rocks on the ground to be included, this is incorrect. For normal (reasonable) accuracy, see my above post about aerial mapping and photometric mapping. 😛 ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [August 23, 2014, 8:26pm UTC](https://boards.straightdope.com/t/measuring-land-on-a-hill-side/696215/18 "2014-08-23T20:26:15Z")
In the US For real estate transactions and property tax parcel calculations the land area is measured as a flat two dimensional plane viewed from the top. ---
**Author:** ![The\_Great\_Unwashed](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/the_great_unwashed/32/4791_2.png) [@The\_Great\_Unwashed](https://boards.straightdope.com/u/The_Great_Unwashed)\ **Post date:** [August 23, 2014, 10:00pm UTC](https://boards.straightdope.com/t/measuring-land-on-a-hill-side/696215/19 "2014-08-23T22:00:16Z")
> [@GusNSpot](#): > > Unless you are demanding the actual surface area of small rocks on the ground to be included, this is incorrect. For normal (reasonable) accuracy, see my above post about aerial mapping and photometric mapping. 😛 Your “post above” mentions neither _aerial-_ nor _photometric- mapping_. I’m not sure why they would help. The problem is absolutely [non-trivial](http://en.wikipedia.org/wiki/Coastline_paradox). ---
**Author:** ![GusNSpot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gusnspot/32/436_2.png) [@GusNSpot](https://boards.straightdope.com/u/GusNSpot)\ **Post date:** [August 23, 2014, 11:01pm UTC](https://boards.straightdope.com/t/measuring-land-on-a-hill-side/696215/20 "2014-08-23T23:01:32Z")
> [@The\_Great\_Unwashed](#): > > Your “post above” mentions neither _aerial-_ nor _photometric- mapping_. I’m not sure why they would help. The problem is absolutely [non-trivial](http://en.wikipedia.org/wiki/Coastline_paradox). My bad, A mapping company is not a survey company ( although many times they have both in house. Most government & civil mapping is done with aerial mapping which includes the use of photogrammetry. Many many civil engineering firm that do subdivision plans use it a lot for calculating run off and dirt moving needs. It is so accurate that it is used in coal pile calculation inventories. Was used to keep track of the progress in the making of the TenTom waterway and used to make the payments to the contractors which was determined by how much dirt they had moved. It is very accurate indeed. 27 years in the business. [Next page](https://boards.straightdope.com/t/measuring-land-on-a-hill-side/696215.md?page=2)