A good specification item, capable of correctly describing a job, helps to obtain a correct price for the work itself right from the design phase.
A description that is too generic does not put the person who has to make a quotation in a position to provide a truthful price for the work or the requested artifact, resulting in a generally skewed price, either too high or too low.

This brief guide aims to put the designer in a position to understand the elements that generate costs in the quantification of the final prices of stone stairs, sills, and thresholds, enabling them to provide the correct quantities during the computation phase that will be needed to provide real prices.
From the perspective of the marble worker, requests are often absolutely incomplete and cannot be correctly quoted. The first element, paradoxically missing, is the clear identification of the material! A pietra serena, a Carrara marble, a Pietra di Rapolano, or a granite will have different costs! And even within these types of material, there are many subcategories: speaking of travertine, light or dark? With or against the grain?

Therefore, first of all, it is necessary to describe as accurately as possible the requested material in terms of type and color.

1. Then the thickness is obviously fundamental. The thicker the material, the more it costs, even in terms of transport to the site.
   Natural stones are generally very resistant to wear, so the choice to increase thicknesses can only be justified by aesthetic parameters, for example in sills or stairs, where the thickness is visible: generally, a greater thickness confers greater prestige to an artifact.
   In a staircase, for example, there is no need to have a greater thickness in the risers, where a thickness of 2 cm is absolutely sufficient. The standard for the treads is instead 3 cm.
2. Another parameter to clearly indicate is the finish of the material: polished or glossy? Brushed? In Pietra di Rapolano or travertine, filled?
   Each of these processes has its own complexity from which a cost derives. Not indicating how we want the stone finished on the surface omits information without which it becomes difficult to make a correct price.
3. And then the edge processing of the slabs. If they are simply sawn, there is no need to indicate anything, but if the edge is visible: do we want it polished and straight beveled? Or with a bullnose finish? Or with a shadow or rebate? All these processes have a cost per linear meter. Therefore, it is necessary to indicate the quantities of edge finishes.
4. In sills, it is also necessary to indicate the quantity, in linear meters, of drip groove. And also whether they will be installed flush with the wall or projecting: the projection requires processing of the 3/5 cm that the sill (or threshold) will project.

The lack of this information will often lead to paying for processes even where not necessary.

Correct specification items follow, which each designer will need to complete with their own indications.

SPECIFICATION ITEM FOR STONE SILL

Sill in ________ (specify chosen stone material as much as possible, in terms of type of stone, color, also describing the surface finish) with a thickness of cm ___ (the sufficient standard is 3 cm). (It would be important to indicate maximum or minimum dimensions of the sills and the total number. Various stones have blocks of different sizes. Knowing the dimensions of the worked pieces helps in a correct quotation. P.s this item is expressed in square meters).

Follows an example of a correct item

Sills in Pietra di Rapolano, Color Pdr 013, filled and polished finish, thickness 3 cm. The size of the pieces will be 45 cm x variable lengths from 70 to 200 cm. The total number of sills will be 70). The sills will project 3 cm from the external wall face and will be equipped with a drip groove. Internally, the thickness of the sill will be covered by the frame (and therefore will not require any finish). The finish of the visible edges will be straight and beveled.

• Material at thickness 3 cm – Total 42.00 sqm
• Straight edge processing – 93 linear meters
• Drip groove processing – 93 linear meters
• Turn processing for 4 cm per side – No. 140

SPECIFICATION ITEM FOR STONE THRESHOLD

Threshold in ________ (specify chosen stone material as much as possible, in terms of type of stone, color, also describing the surface finish) with a thickness of cm ___ (the sufficient standard is 3 cm). (It would be important to indicate maximum or minimum dimensions of the thresholds and the total number. Various stones have blocks of different sizes. Knowing the dimensions of the worked pieces helps in a correct quotation. P.s this item is expressed in square meters).

Follows an example of a correct item

Thresholds in Pietra di Rapolano, Color Pdr 013, filled and polished finish, thickness 3 cm. The size of the pieces will be 45 cm x variable lengths from 70 to 200 cm. The total number of thresholds will be 70). The thresholds will project 3 cm from the external wall face and will not be equipped with a drip groove. Internally, the thickness of the threshold will align with the floor (and therefore will not require any finish). The finish of the visible edges will be straight and beveled.

• Material at thickness 3 cm – Total 42.00 sqm
• Straight edge processing – 93 linear meters
• Turn processing for 4 cm per side – No. 140

SPECIFICATION ITEM FOR STONE STAIRCASE

Staircase in ________ (specify chosen stone material as much as possible, in terms of type of stone, color, also describing the surface finish) with a thickness of cm ___ (the sufficient standard is 3 cm for the tread and 2 cm for the riser). It is very important to indicate whether the staircase is enclosed between two walls or has one side visible. This determines the need for processing on one short end of the staircase and the quantification of the skirting pieces for stairs required (if requested). It is also important to quantify any square meters of stairs that will not be made from rectangular steps, but trapezoidal, because the cost of the pieces for the realization of the fans is greater than the straight-cut pieces (it would be important to indicate the dimensions of the treads and risers and the total number. Various stones have blocks of different sizes: knowing the dimensions of the worked pieces helps in a correct quotation. P.s this item is expressed in square meters).

Follows an example of a correct item

Staircase in Pietra di Rapolano, Color Pdr 013, filled and polished finish, thickness 3 cm. The treads will be 35×120 cm with a thickness of 3 cm. The risers will be 120×14 cm with a thickness of 2 cm. There will be 120 treads and 120 risers to be made, of which 60 are enclosed and 60 open on one side. The finish of the visible edges will be straight and beveled. The staircase includes skirting boards.

• Material at thickness 3 cm – Total 50.40 sqm
• Material at thickness 2 cm – Total 20.16 sqm
• Straight edge processing – 72 linear meters
• Short end tread processing – No. 140
• Skirting board in two pieces for each riser. No. 180
• Skirting board for landings h. 8 cm – 20 linear meters
• Floor for landings 40x40x1.3 – 15 sqm

(N.B. quantities are not exactly calculated)

Staircase in Pietra di Rapolano, FANS, Color Pdr 013, filled and polished finish, thickness 3 cm. The fans will be no. 12 and on a staircase 120 cm wide, with a thickness of 3 cm. The risers will be 150×14 cm with a thickness of 2 cm. The finish of the visible edges will be straight and beveled. The staircase includes skirting boards.

• Material at thickness 3 cm – Total 8.64 sqm
• Material at thickness 2 cm – Total 2.50 sqm
• Straight edge processing – 18 linear meters

(NB. quantities are not exactly calculated)

By adhering to these items, those who will carry out the quotation of the requested artifacts will be able to provide a much more accurate and definitive quotation, whose variation will depend only on the quantification of the final executive measures, detectable on site.

We remain available for suggestions and advice that may become necessary during the design phase.